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[MCQ’s]Production Process

Exit Intent

Module 01

1. Which of the following statement is true?
a) Casting is the replica of the object to be cast
b) Pattern is the replica of the casting object
c) Casting and the pattern are same things
d) Molten material is casted into the casting cavity
Answer: b
Explanation: Pattern is the replica of the object. Except for the core prints and allowances, the pattern exactly resembles the casting.

2. Which of the following carries the mould cavity where the metal is to be poured?
a) Casting
b) Pattern
c) Sand
d) Core
Answer: b
Explanation: For casting to be made, the pattern is filled with the molten material and then it is allowed to be solidified, using proper cooling rates before it is extracted out.

3. Which of the following is ‘not’ an allowance given to the pattern for casting?
a) Shrinkage
b) Draft
c) Hole
d) Machining
Answer: c
Explanation: A hole is made during the machining or finishing of the casting and is not a type of allowance given to the pattern.

4. The quality of the final product is not dependent on _______________
a) Method of withdrawal of pattern
b) Allowance provided to the pattern
c) The complexity of the casting
d) The metal used in Casting
Answer: d
Explanation: Metal used in casting is a concern till its viscosity affect the flow or occupation to the cavity. This does not affect the final product physically, once the metal has solidified.

5. The life of a pattern is most likely to depend upon which of the following term?
a) Number of castings produced
b) Type of cooling rate of the casting
c) Size of the casting
d) Size of the pattern
Answer: a
Explanation: Obviously, the more casting produced means more exposure of the pattern to the elevated temperature of molten metals and hence, slowly causing distortion to the sand grains as well as the pattern material.

6. What is the function of cores in the casting process?
a) To support the pattern
b) To provide differential cooling rates at specific portions
c) To make holes and cavities
d) For ease of flow of the molten material
Answer: c
Explanation: Cores are the elements used to provide hollow cavities and holes in the pattern which are difficult or non profitable to be given after the casting is done by machining.

7. Which of the following is ‘not’ an advantage of the usage of pattern in a casting of metals?
a) Using patterns to cast objects, less time is consumed for mass production
b) It is cost efficient and profitable for mass production
c) Production of the pattern requires extra effort to cast the object
d) Cores in the pattern could be used to decrease the amount of machining done for making cavities
Answer: c
Explanation: Production of patterns requires additional efforts but is justified for mass production only, where more products are formed in less time and overcomes the effort and cost of making patterns.

8. A draft allowance is provided to ___________
a) All linear faces
b) Only the interior dimensions
c) Only the exterior dimensions
d) Only the dimensions that are perpendicular to the parting plane
Answer: d
Explanation: The draft allowance is used for those dimensions which are perpendicular to the parting plane, to give out a tapered face which is machined later.

9. Which of the following factor is not considered while selecting a kind of pattern?
a) Quantity of casting
b) Types of moulding method
c) Shape of the casting
d) Nature of moulding process
Answer: d
Explanation: Nature of moulding process is a factor used selecting pattern materials, whereas the quantity of casting, types of moulding method and shape of the casting are used for selecting a type of pattern.

10. Which type of pattern should be used for making stuffing box of the steam engine?
a) One piece pattern
b) Split Pattern
c) Sweep pattern
d) Gated pattern
Answer: a
Explanation: One piece pattern operations for moulding are used for manufacturing a small number of casting only. Hence, a stuffing box can be casted with this type of pattern.

11. In a three piece pattern moulding arrangement, what keeps the alignment between the two parts of the pattern?
a) Cope
b) Drag
c) Dowel pins
d) Cheek
Answer: c
Explanation: Cope and drag are the portions of upper and lower part of the split and cheek form the middle one. Dowel pins are used for the alignment work in the pattern.

12. Piston rings are produced using which pattern?
a) Sweep pattern
b) Gated pattern
c) Match plate pattern
d) Loose piece pattern
Answer: c
Explanation: Match plate pattern are usually used for manufacturing small castings on a big scale. Hence, piston rings of the engine are made using this pattern.

13. Match Plate pattern consumes more time in moulding operations than loose piece pattern.
a) True
b) False
Answer: b
Explanation: In loose piece pattern, the pattern is drawn out first and then the loose pieces, which consumes more time. On the other hand, match plate casting is used for small casting only, hence operates in less time.

14. Which of the following pattern operation is cheapest?
a) Sweep pattern
b) Gated pattern
c) Match plate pattern
d) Skeleton pattern
Answer: d
Explanation: Skeleton pattern uses the least amount of material for the operations on pattern and therefore, it does not need a lot of investment on its materials, making it inexpensive.

15. Which pattern operation is used for manufacturing wheel rims?
a) Follow board pattern
b) Segmental pattern
c) Sweep pattern
d) Gated pattern
Answer: b
Explanation: In segmental pattern, it does not revolve continuously to make the mould, but completes one part of the mould and then goes to make the next portion. Hence, such type of pattern is used for making wheel rims and big gears.

16. The skeleton pattern is filled with sand.
a) True
b) False
Answer: a
Explanation: In skeleton pattern, the skeleton is made up of wood and then sand is added to the pattern. After putting the sand, then the pattern is rammed.

17. Co2 moulding is mainly used for the increase in strength and hardness of the moulds and cores.
a) True
b) False
Answer: a
Explanation: Mould is prepared by adding sodium silicate binder. Co2 gas is supplied to the mould for sufficient time. It reacts with sodium silicate and produces silica gel which has better bonding properties. Due to this strength and hardness of the large sized moulds and cores can be increased.

18. How much percentage of sodium silicate (Na2SiO3) is added to the sand mixture in Co2 moulding?
a) 0 to 2 %
b) 2 to 6 %
c) 6 to 10 %
d) 10 to 14 %
Answer: b
Explanation: No other things like clay, water and resins are added to the sand except sodium silicate, which reacts with the sand mix to increase the flow-ability to fill up corners and intricate contours. Then the Co2 is supplied to the mould and reaction takes place as follows:
Na2SiO3 + Co2 —–> SiO2 + Na2Co3
Where, SiO2 is having gelling action (Silica gel).

19. Continuous passing of Co2 through the mould can decrease the strength of mould and results in a weak mould.
a) True
b) False
Answer: b
Explanation: Continuous passing of Co2 always results in a strong and hard mould. More the passing of Co2 more will be the strength of the mould. Only the drawback is the decrease in permeability and collapsibility of the mould. Much passing of Co2 gas results into difficult breathing of the mould.

20. How much time (in a minute) is usually required for the passing of Co2 through the mould?
a) One
b) Two
c) Five
d) Seven
Answer: a
Explanation: In Co2 moulding, mould of sand is hardened by passing of Co2 for about one minute. The Co2 gas forms a weak acid that hydrolyzes the sodium silicate (Na2O, SiO2) solution to form amorphous silica gel which acts as the bond and sodium silicate itself also provides some bonding action.

21. Additives can be used for the non-ferrous application to avoid the poor collapsibility of the mould.
a) True
b) False
Answer: b
Explanation: In Co2 moulding, poor collapsibility of the mould is a major disadvantage. Although some additives are used for the improvement in the properties of ferrous metal castings, these additives which are added to the sand mixture, cannot be applicable for the non-ferrous applications.

22. Sometimes over-gassing can cause the sticking of pattern to the mould in Co2 moulding.
a) True
b) False
Answer: a
Explanation: In Co2 moulding, over-gassing and under-gassing can affects the properties of cured sand adversely. When the continuous passing of Co2 is done for long time, this may results into sticking of pattern with the mould which cannot be removed easily, so proper care should be taken while passing of Co2 gas.

23. It is very safe to use Co2 in Co2 moulding, so it eliminates the use of any shielding apparatus.
a) True
b) False
Answer: a
Explanation: In Co2 moulding, the process uses relatively safe carbon dioxide gas and it does not cause any of the sand disposal problems or any kind of odour while mixing and pouring. So the using of carbon dioxide gas is very safe to human operators. And so, no any equipment is required for the shielding.

24. Which of the following additives are added to the sand in Co2 moulding for the improvement in collapsibility of the sand?
a) Copper oxide
b) Wood flour
c) Aluminium oxide
d) Oil
Answer: c
Explanation: After the preparation of the sand mixture by adding sodium silicate to the sand, the next step is to add additive, in which mainly aluminium oxide is added and sometimes molasses are also added to impart the favorable properties and for the improvement in the collapsibility of the sand mix.

25. Co2 moulding process is an ideal process, where speed and flexibility is the prime requirement.
a) True
b) False
Answer: a
Explanation: In Co2 moulding, moulds and cores of varied sizes and shapes can be formed, this is mainly achieved by the using of binder sodium silicate that can binds the sand in any shape and size, and that is further tightened by the passing of Co2 gas. This makes the moulding process very fast and flexible, so this process is more economical, where speed and flexibility is the prime requirement.

26. Moisture from the mould can be removed by using of dryer or heater in Co2 moulding.
a) True
b) False
Answer: b
Explanation: In Co2 moulding, water is never added while preparing a sand mixture. Instead of water, sodium silicate is added to act as a binder. Hence the moisture is completely eliminated from the mould. So, this process provides great dimensional tolerances and high accuracy in the production of castings.

27. Co2 moulding is a kind of sand moulding, but it is not economical than the green sand moulding.
a) True
b) False
Answer: a
Explanation: Better surface finish of castings with close tolerances are produced by Co2 moulding, but it is still not economical than the green sand moulding because this process uses expensive devices like Co2 cylinder, hoses, regulator, hand held applicator gun or nozzle etc., and the processes in green sand moulding are simple and no expensive devices are required, due to this, green sand moulding is more economical.

28. Which of the following synthetic resins are used for mixing with sand in shell moulding?
a) Thermosetting resins
b) Epoxy resins
c) Fiber glass resins
d) Kevlar
Answer: a
Explanation: The synthetic resins used in shell moulding are essentially thermosetting resins, which get hardened by heat. Phenol formaldehyde resins are mostly used, which combines with sand to form a proper mixture for shell moulding. The mixture formed has high strength and resistance to heat.

29. Grain size of the sand particles has no affects on the surface finish of the casting.
a) True
b) False
Answer: b
Explanation: Generally, for the preparation of shell moulding sand, dry and fine sand that is completely free of the clay is used. The grain size to be chosen depends on the surface finish required on the casting. Too much fine a grain size requires a large amount of resin, which makes the mould expensive.

30. In shell moulding sand preparation, the resin is combined with a catalyst (hexa) to develop the_____
a) thermoplastic characteristics
b) toughness of the resin
c) thermosetting characteristics
d) viscosity of the resin
Answer: c
Explanation: The phenolic resins used in shell moulding have excess of phenol and acts like a thermoplastic material. During coating with sand the resin is mixed with a catalyst such as hexa methylene tetramine (hexa) in a proportion of 14 to 16 % so as to develop the thermosetting characteristics.

31. Which of the following compositions of the shell sand is used for avoiding of thermal crack during pouring?
a) Silica sand
b) Zircon sand
c) Resin
d) Additives
Answer: d
Explanation: Generally, additives are added to the sand mixture to improve the surface finish and also for the avoiding of any thermal crack during pouring. Some of the additives used are coal dust, manganese dioxide, calcium carbonate, pulverized slag and ammonium boroflouride.

32. Which of the following lubricants is added to the resin sand mixture for better flowability of the sand?
a) Lead stearate
b) Magnesium stearate
c) Sulphur stearate
d) Zinc stearate
Answer: d
Explanation: Some lubricants such as zinc stearate and calcium stearate are added to the resin sand mixture to improve the flowability of the sand, which helps in covering of maximum part of the metallic pattern efficiently and also permit easy release of the shell from the pattern.

33. Which of the following devices is used for the mixing or complete formation of the shell sand mixture?
a) Chucker
b) Mueller
c) Semi circular roller
d) Semi cylindrical roller
Answer: b
Explanation: Sand, hexa and additives, which are all dry, are mixed inside a Mueller for a period of 1 minute, then the liquid resin is added and mixing is done for another 3 minutes. Then by introducing cold or warm air into the Mueller, mixing is continued till all the liquid is removed from the mixture and coating of the grains is achieved to the desired degree.

34. Which of the following metals is used for the preparation of patterns in shell moulding?
a) Aluminium
b) Copper
c) Grey cast iron
d) Brass
Answer: c
Explanation: Generally, metal patterns with the associated gating are used. The metal used for preparing patterns is grey cast iron; it is mainly used because of its easy availability and good stability at the temperatures involved in the process. Sometimes, additional risers are also required as the cooling in shell moulds is slow.

35. Which of the following devices is used for the formation of shell mould in the shell moulding procedure?
a) Air roller
b) Re-circulating ball roller
c) Chucker
d) Dump box
Answer: d
Explanation: A silicone release agent is sprayed on the heated metallic pattern which is fixed to a dump box, wherein the coated sand of sufficient amount is filled in. Then the dump box is rotated so that the coated sand falls on the heated pattern and the heat liberating from the pattern melts the resin and causes sand mixture to adhere to the pattern.

36. At the last of shell moulding procedure, the Dump box is rotated backward for adhering of as much as the possible amount of sand to the metallic pattern.
a) True
b) False
Answer: b
Explanation: When after the achieving of a desired thickness of the shell, the dump box is rotated backward by 180 degrees so that the excess of sand falls back into the box, leaving the formed shell intact with the pattern. Thickness of the shell depends on the temperature of the pattern and the coating time of sand in contact with the heated pattern.

37. Over-curing or under-curing of the shell mould, leads to the generation of sophisticated problems in the shell mould.
a) True
b) False
Answer: a
Explanation: For the curing of the shell mould, it is kept in an electric or gas fired oven. The curing of the shell should be done as per requirements only because over-curing can cause the mould to break down as the resin would burn out. And under-curing may result in blow holes in the casting or the shell may break during handling.

38. There is no need for any external support for the shells at the time of pouring of molten metal.
a) True
b) False
Answer: b
Explanation: Since the shells are thin, and pouring of molten metal into the shells may cause an imbalance which further leads to failure of the castings. So to avoid this, it may require some outside support to withstand the pressure of the molten metal and to form the castings efficiently with proper balance.

39. Which of the following types of clamping is mostly performed for the joining of shells?
a) Mechanical
b) Electrical
c) Pneumatic
d) Hydraulic
Answer: a
Explanation: The prepared shells are joined together by mechanical clamping or sometimes adhesive bonding is also preferred for joining of shells. The resin used as an adhesive may be applied at the parting plane before mechanical clamping and then allowed for 20 to 40 seconds to achieve necessary bonding. Then the shell mould becomes ready for pouring of molten metal.

40. Which of the following considerations distinguish die casting from the permanent mould casting?
a) Moulding material
b) Way of pouring molten metal
c) Coating on mould
d) Size of castings
Answer: b
Explanation: Die casting is almost the same as permanent mould casting, in that both the processes use reusable metallic dies. Die casting involves the preparation of components by injecting molten metal at high pressure into a metallic die; this way of pouring of molten metal distinguishes die casting from the permanent mould casting.

41. It is easy to produce any complex shapes and narrow sections in the die casting.
a) True
b) False
Answer: a
Explanation: In die casting, as the metal is forced in under pressure compared to the permanent mould casting, it is also known as pressure die casting. Because of involvement of high pressure in die casting, any type of complex shapes, narrow sections and fine surface details can easily be produced.

42. Due to the presence of ejector die, there is no need of lubricant for the removal of casting from the dies.
a) True
b) False
Answer: b
Explanation: For the easy removal of casting from the dies, lubricant is required. The lubricant is sprayed on the die cavity manually or by the auto lubrication system so that the casting will not stick to the die. Ejector die only moves out itself for the extraction of the castings, but the lubricant is essential for the easy removal of the castings.

43. A single piece or unitary part of the metallic die is used for making castings in die casting.
a) True
b) False
Answer: b
Explanation: Die casting mainly has two parts. One part is the stationary half or cover die, which is fixed to the die casting machine. The second part is the moving part or ejector die that is moved out for the extraction of the casting. The casting cycle basically starts when the two parts of the die are apart.

44. Which of the following ways of cooling is used for the maintaining of die temperature?
a) Natural air cooling
b) Forced air cooling
c) Water channels cooling
d) Liquid nitrogen cooling
Answer: c
Explanation: As the metallic die is used in the die casting as a mould, so the extraction of heat from the molten metal will not be easy. So for maintaining proper die temperature, water cooling channels are used near the castings through the cover and ejector die. This makes the proper solidification of the castings.

45. In cold chamber die casting, rapid cooling of the castings is done as compared to the hot chamber die casting.
a) True
b) False
Answer: b
Explanation: In hot chamber die casting, the holding furnace for the liquid metal is integral with the die casting machine, whereas in cold chamber die casting, the metal is melted in separate furnace and then poured into the die casting machine with the help of a ladle for each casting cycle which is also called shot.

46. In the hot chamber die casting process, which of the following parts is used for the pumping of liquid metal into the cavity?
a) Accumulator
b) Slug
c) Guide pin
d) Gooseneck
Answer: d
Explanation: A gooseneck is used for the pumping of liquid metal into the die cavity. It is made of ductile iron or of cast steel. The gooseneck is submerged in the holding furnace containing the molten metal. Then a plunger which is hydraulically operated moves up in the gooseneck to open the entry port for the entry of liquid metal into the gooseneck.

47. In hot chamber die casting processes, downward motion of plunger in the gooseneck leads to injection of molten metal into the cavity with high pressure.
a) True
b) False
Answer: a
Explanation: In the gooseneck, the highest position of the plunger facilitates the filling of the gooseneck by the liquid metal. Then the plunger starts moving down to force the metal in the gooseneck to be injected into the die cavity. The metal is then held at the same temperature till it is solidified.

48. In hot chamber die casting, the plunger is also used for taking back of unused molten metal to the gooseneck after the fulfilling of the cavity.
a) True
b) False
Answer: a
Explanation: After the filling of molten metal into the cavity, somewhat of melt still remains in the nozzle or sprue part. To avoid the wastage of melt, plunger is used, which by moving back returns the unused liquid metal to the gooseneck. This process saves a lot of molten metal and hence economizes the production.

49. Which of the following materials is not suitable to be cast by a hot chamber die casting process?
a) Lead
b) Tin
c) Aluminium
d) Zinc
Answer: c
Explanation: The hot chamber die casting process is basically used for the low melting temperature alloys. But, for material such as aluminum, its high melting temperature makes it difficult to cast by hot chamber die casting process, because continuous contact of gooseneck with the molten metal can destroy the gooseneck material.

50. Using of the ladle in the cold chamber die casting has no affects on contact time between the molten metal and the shot chamber.
a) True
b) False
Answer: b
Explanation: When the molten metal is ladled into the shot chamber of the machine either manually by a hand ladle or by an auto ladle, which is a form of a robotic device. This process reduces the contact time between the molten metal and the shot chamber, so the high melting temperature materials can be cast easily.

51. The chances of defects in the castings by cold chamber die casting are more than the castings produced by hot chamber die casting.
a) True
b) False
Answer: a
Explanation: Since the metal is ladled into the machine from the furnace, so it may lose the superheat and may cause defects in the castings such as cold shuts. Also, there is a main disadvantage in the cold chamber die casting process is the longer cycle time needed as compared to the hot chamber die casting process.

Module 02

1. Which of the following is not a type of arc welding?
a) Plasma
b) Electro-slag
c) Submerged
d) Air-acetylene
Answer: d
Explanation: Among the following, plasma arc, electro-slag and submerged arc are few of the types of arc welding. Air-acetylene is one of the forms of gas welding processes.

2. Which of the following is not a type of resistance welding?
a) Seam
b) Projection
c) Electro-slag
d) Spot
Answer: c
Explanation: Among the following, seam, projection and spot are few of the types of resistance welding. Electro-slag is one of the forms of gas welding processes.

3. Which of the following materials are not suited for cold welding?
a) Brass
b) Steel
c) Silver
d) Gold
Answer: b
Explanation: Cold welding process is not very suitable for alloys like steel, the reason being, cold welding cannot take place excellently in ferrous materials. Steel contains high amount of iron, hence it cannot be cold welded.

4. What is the cross-sectional shape of a thermoplastic welding rod?
a) Triangular
b) Hexagonal
c) Square
d) Pentagonal
Answer: a
Explanation: A welding rod or a thermoplastic welding rod is used mainly in plastic welding. The rod should not be very porous or it may catch voids. This rod has a cross sectional shape triangular or circular.

5. Which of the following is not a type of related processes?
a) Soldering
b) Percussion
c) Brazing
d) Hard-pressing
Answer: b
Explanation: Among the following, soldering, pressing and hard-pressing are few of the types of related processes. Percussion is one of the forms of resistance welding processes.

6. Laser is classified under newer beam.
a) True
b) False
Answer: a
Explanation: There are various types of welding processes, one of them is a newer welding process. Under this, there are two types, one is electron-beam and another is the use of laser.

7. Which of the following is not a type of solid state welding?
a) Projection
b) Ultrasonic
c) Friction
d) Diffusion
Answer: a
Explanation: Among the following, ultrasonic, friction and diffusion are a few of the types of related processes. Percussion is one of the forms of resistance welding processes.

8. What is the density of the plastic used in speed tip welding?
a) 916 kg/m3
b) 923 kg/m3
c) 946 kg/m3
d) 982 kg/m3
Answer: c
Explanation: The plastic which is used in the process of speed tip welding is polypropylene or polypropene. It is classified under thermoplastics materials. The density of polypropylene is 946 kg/m3 and it starts melting at 130°C.

9. Which of the following could be considered as a related process?
a) Explosive
b) Oxy-Hydrogen welding
c) Oxy-Acetylene cutting
d) Electron-beam
Answer: c
Explanation: Among the following, oxy-acetylene cutting is considered as a related process. Explosive is a type of solid state welding. Electron-beam is a type of newer welding and oxy-hydrogen welding is a form of gas welding.

10. A liquid phase has to be used in cold welding.
a) True
b) False
Answer: b
Explanation: It is hot welding that a liquid or a molten state is used for the joining of two pieces of metal. But in cold welding, there is no use of a liquid phase, that is, joining is done without using heat.

11. Oxy-acetylene process is most suited for which of the following process of joining?
a) Metal wires
b) Metal sheets
c) Metal tubes
d) Metal bars
Answer: b
Explanation: Oxy-acetylene process is most suited for the joining of metal sheets or for joining metal plates which are having a thickness of 2mm to 50mm. While joining, the molten metal flows together to form a continuous joint.

12. For what thickness of a material, in an oxy-acetylene is a welding rod used?
a) 10 mm
b) 15 mm
c) 20 mm
d) 25 mm
Answer: b
Explanation: Oxy-acetylene processes are mainly used for the joining of metal sheets or for joining metal plates which are having a thickness of 2mm to 50mm. When the thickness of the material is more than 15 mm, an additional filler metal is added like a welding rod.

13. What is the flame temperature of city gas?
a) 1500°C
b) 1600°C
c) 1700°C
d) 1800°C
Answer: c
Explanation: City gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 3 mm. The flame temperature of city gas is approximately about 1700°C.

14. In a neutral flame, what is the temperature in the inner core?
a) 3200°C
b) 2100°C
c) 1250°C
d) 2700°C
Answer: a
Explanation: When equal amount of oxygen and acetylene is made to react in a torch, a neutral flame gets produced. The inner core has a temperature of 3200°C, whereas the tip of the neutral flame has a temperature of 1250°C.

15. What is the flame temperature of water gas?
a) 2500°C
b) 2800°C
c) 2300°C
d) 3100°C
Answer: c
Explanation: Water gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 8 mm. The flame temperature of water gas is approximately about 2300°C.

16. Carburising flame has excess of oxygen supply.
a) True
b) False
Answer: b
Explanation: None.

17. What is the flame temperature of methane?
a) 2000°C
b) 1200°C
c) 2700°C
d) 3300°C
Answer: a
Explanation: None.

18. Oxidizing flame has equal volumes of oxygen and acetylene supply.
a) True
b) False
Answer: b
Explanation: A neutral flame is the one in which there is an equal amount of supply of oxygen and acetylene. A carburising flame is the one in which the supply of acetylene is much more than that of oxygen and an oxidizing flame is the one where there is ample supply of oxygen compared to acetylene.

19. What is the flame temperature of acetylene?
a) 1700°C
b) 2200°C
c) 2800°C
d) 3200°C
Answer: d
Explanation: Acetylene gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 50 mm. The flame temperature of acetylene gas is approximately about 3200°C.

20. What is the flame temperature of hydrogen?
a) 2000°C
b) 1200°C
c) 2700°C
d) 3300°C
Answer: c
Explanation: None.

21. Which of the following types of fuel gas is commonly used in gas welding?
a) Biogas
b) Coal gas
c) Acetylene
d) Methane
Answer: c
Explanation: Gas welding is usually referred as oxy welding or oxy-fuel welding which is a process of joining metallic materials by application of heat produced by the gas flame. In gas welding, acetylene is commonly used as fuel gas which mixed with proper proportion of oxygen in a mixing chamber of welding torch. Gas welding can produce a hot flame of temperature about 3000-3500 ⁰C.

22. In gas welding, the joint can be made even much stronger than the original.
a) True
b) False
Answer: a
Explanation: In gas welding, various metals like cast iron, steel, aluminium, copper etc. can be used for joining operation. First they brought into a molten state and then a fusion is taking place between two pieces of metal in such a way that the point of fusion closely approaches the strength of the metal fused. In this process, the union or joint can be made even much stronger than the original.

23. Acetylene is a hydrocarbon which molecule is made up of two carbon atoms and four hydrogen atoms.
a) True
b) False
Answer: b
Explanation: In gas welding, acetylene is used as a fuel gas which is a hydrocarbon like other as propane, methane etc. However, it generally differs from those hydrocarbons in a manner that its molecule is made up of two carbon atoms and two hydrogen atoms. And the carbon atoms are joined with hydrogen atoms by making a triple bond.

24. Acetylene is a blue color gas which mixed with oxygen to produce a hot flame.
a) True
b) False
Answer: b
Explanation: In gas welding, acetylene is basically a colorless gas with a very distinctive odour and highly combustible when it is mixed with oxygen. Acetylene gas is formed by mixing the calcium carbide with water and then it is composed, which forms a compound of carbon and hydrogen having the chemical formula C2H2.

25. Gas welding is mainly suited for welding of thin sheets, small diameter pipes and tubes.
a) True
b) False
Answer: a
Explanation: Gas welding process is mainly suited for the welding of a thin sheet, tubes, and small diameter pipe because it cannot provide very high temperature as compared to that provided by the electric arc welding. This method of joining is also used for repairing work, maintenance and in body shops.

26. Acetylene is a non-toxic gas which can be kept or stored in a cylinder at any pressure.
a) True
b) False
Answer: b
Explanation: In gas welding, acetylene is used as a fuel gas which produces hot flame when it is mixed with oxygen. Acetylene may be non-toxic gas, but if it is stored in a cylinder at more than the pressure of 2 bar, then the acetylene becomes self explosive, that’s why the pressure of stored acetylene should be maintained with great care.

27. Single stage gas regulator cannot be used in cold weather for regulating the acetylene or oxygen gas.
a) True
b) False
Answer: a
Explanation: Single stage converter is used to reduce the pressure from the cylinder pressure to the welding pressure, which can take place in a single stage. However, it tends to freeze in cold weather. This is because an abrupt expansion and resulting drop in initial pressure makes rapid cooling of the gas and may cause ice formation in the presence of moisture.

28. In gas welding, the hoses are mainly used for making the connection between gas torch and regulators.
a) True
b) False
Answer: a
Explanation: In gas welding, the hoses are mainly used for making connections between the gas torch and the regulators, which should be made strong, light and flexible enough to make torch movements smooth. In general, welding hose can be of two types that are twin welding hose and double welding hose.

29. A flashback is a condition in gas welding, when the pure methane gas is used as fuel gas instead of acetylene.
a) True
b) False
Answer: b
Explanation: In gas welding, a flashback is a condition in which the flame burns inside the gas torch. Flashback is generally caused by improper mixing of gases, which further increases the rate of flame propagation to high extent that the flame goes back to the mixing chamber. If it is not stopped, the flame may burn the mixture and may travel back into the cylinder.

30. A welding torch is mainly used for mixing and burning the gases in the desired proportions.
a) True
b) False
Answer: a
Explanation: In gas welding, a welding torch is mainly used for mixing oxygen and acetylene in the desired proportions. It is also used for burning the mixture at the end of the tip, and also provides a mean for moving and directing the flame front. Welding torch can be of high pressure type or low pressure type.

31. Which kind of resistance is experienced in upset butt welding?
a) Electric resistance
b) Magnetic resistance
c) Thermal resistance
d) Air resistance
Answer: a
Explanation: In the making of an upset butt welding, there are jaws made of copper, into which the part to be welded is put, and hence a solid contact is made. At this point of contact, while the current flows, it gets transformed into heat because of electric resistance.

32. Which of the following can be easily be welded from flash butt welding process?
a) Tin
b) Lead
c) Cast irons
d) Carbon steel
Answer: d
Explanation: In flash butt welding process, the welding of materials like steels and other iron alloys are easy to weld, except for cast iron. The welding of materials like tin, lead, zinc and antimony cannot be welded using flash butt method.

33. Electrodes used in spot welding are made up of which material?
a) Only Copper
b) Copper and tungsten
c) Copper and chromium
d) Copper and aluminium
Answer: d
Explanation: The electrodes that are employed in the spot welding are required to possess a high amount of electrical and thermal conductivity. Hence, they are primarily made up of copper or copper and tungsten or copper and chromium.

34. How are the metals to be welded connected to each other in spot welding?
a) Electric contact
b) Magnetic field
c) Mechanical pressure
d) Direct contact
Answer: c
Explanation: In spot welding process, the metal or the alloy parts which are to be welded, are heated in their in their zones. To bring these parts in contact with one another, mechanical pressure is applied, causing them to connect.

35. Which of the following method is not used in applying pressure in spot welding process?
a) Hand lever
b) Foot lever
c) Air pressure
d) Hydraulic cylinder
Answer: a
Explanation: None.

36. Up to what thickness, can steel be welded using spot welding process?
a) 10 mm
b) 11 mm
c) 12 mm
d) 13 mm
Answer: c
Explanation: In spot welding process, to bring the heated parts in contact with one another, mechanical pressure is applied. This pressure can be of three types, by using foot lever, by providing air pressure or by using a hydraulic cylinder. The use of these methods allows steel or other metal parts to be welded up to a thickness of 12 mm.

37. What is the maximum power supply needed for the working of spot welding process?
a) 135 kVA
b) 140 kVA
c) 145 kVA
d) 150 kVA
Answer: d
Explanation: Spot welding can be used for all types of ductile metals. It can also be employed for structures of sheet metals, and can be applied for making of boxes and cans. For its applications, the maximum power that can be needed for this process is 150 kVA.

38. What is the minimum power supply needed for the working of spot welding process?
a) 10 kVA
b) 14 kVA
c) 6 kVA
d) 22 kVA
Answer: a
Explanation: None.

39. Upset butt welding is majorly used in the making of automobile parts.
a) True
b) False
Answer: b
Explanation: Upset butt welding is mainly used for the manufacture of welding bars, rods, wires or tubing. For the manufacture of automobile parts, such as axles, wheels or frames, flash butt welding is extensively used.

40. In flash butt welding, the forced out metal is called flash.
a) True
b) False
Answer: a
Explanation: In flash butt welding process, there is a light contact between the edges. A high voltage is supplied when the flashing action takes place. In this process, the metal that is forced out, is called as flash.

41. At what temperature, does fusion welding takes place?
a) 850°C
b) 900°C
c) 950°C
d) 1000°C
Answer: b
Explanation: The process of fusion welding can be used for joining metal to a metal or a metal can be joined to a ceramic. For the joining of this process, a temperature of 900°C is provided for the approach.

42. Which of the following is not a type of diffusion welding?
a) Gas-pressure welding
b) Vacuum fusion welding
c) Eutectic fusion bonding
d) Eutectoid fusion welding
Answer: d
Explanation: Diffusion welding is has three basic techniques which are incorporated by it. These three basic techniques are, gas – pressure welding, vacuum fusion welding and eutectic fusion welding.

43. What is the minimum frequency used in ultrasonic welding?
a) 10,000 Hz
b) 20,000 Hz
c) 30,000 Hz
d) 40,000 Hz
Answer: b
Explanation: The process of ultrasonic welding is mainly used for the joining of similar metals or dissimilar metals using vibration energy, by way of high frequency. The minimum frequency needed for this purpose is 20,000 Hz.

44. What is the maximum frequency used in ultrasonic welding?
a) 30,000 Hz
b) 40,000 Hz
c) 50,000 Hz
d) 60,000 Hz
Answer: d
Explanation: None.

45. In what conditions are the parts kept before welding in ultrasonic welding method?
a) Low static pressure
b) High static pressure
c) Low moving pressure
d) High moving pressure
Answer: a
Explanation: In ultrasonic welding method, the parts which are to be joined, are kept clamping to one another in between of supporting member and the welding tip. This clamping is done at a low static pressure.

46. What is the maximum thickness that can be welded in ultrasonic welding?
a) 1.8 mm
b) 2.1 mm
c) 2.3 mm
d) 2.5 mm
Answer: d
Explanation: Weldings such as spot welding or continuous seam welding can be done through ultrasonic welding. The maximum thickness that can be achieved varies depending on the metal. The maximum thickness can be that can be welded is 2.5mm.

47. Electric currents are passed is ultrasonic welding.
a) True
b) False
Answer: b
Explanation: In ultrasonic welding method, the parts which are to be joined, are kept clamping to one another in between of supporting member and the welding tip. In doing this, no current is required to be passed through the metal, and usually, no heat is needed for this too.

48. What is the minimum thickness that can be welded in ultrasonic welding?
a) 0.58 mm
b) 0.21 mm
c) 0.38 mm
d) 0.92 mm
Answer: c
Explanation: None.

49. Which of the following is not a factor for explosive welding?
a) High relative velocity
b) Less amount of plastics
c) Proper orientation
d) High pressure
Answer: b
Explanation: While considering for explosive welding, the factors that one needs to understand is that, there has to be high relative velocity. There should be proper orientation and it needs to be kept under high amount of pressure.

50. ‘α’ is the angle between target plate and flyer plate.
a) True
b) False
Answer: a
Explanation: The workpiece which has its position fixed is called as the target plate and the other plate is called as flyer plate. The distance between the two plates is denoted by ‘d’ and the angle between them is denoted by ‘α’.

51. After the achievement of welding temperature, electrical connections are established to complete the weld.
a) True
b) False
Answer: b
Explanation: The superheated melt is heated from the crucible gets poured around the metal parts. As the welding temperature is achieved, there is an application of mechanical pressure to the weld.

52. What is the magnitude of temperature produced in a thermit reaction?
a) 2500°C
b) 3000°C
c) 3500°C
d) 4000°C
Answer: b
Explanation: Thermit welding is called as fusion welding. A superheated melt operates in this type of melt. The heat that is produced has the temperature approximately twice than that of the melting point of steel, which is about 3000°C.

53. Thermit welding is used for making rail tracks.
a) True
b) False
Answer: a
Explanation: A superheated melt operates in this type of melt. The production of pipes, rail tracks, shafts or big gears can be done using thermit pressure welding. Thermit welding is called as fusion welding.

54. In an iron thermit, how many moles of aluminium reacts with three moles of iron oxide to give nine moles of iron?
a) 6
b) 7
c) 8
d) 9
Answer: c
Explanation: The thermit process, which is used for welding depends on the chemical reaction between oxide of iron and aluminium metal. According to this reaction, when 8 moles of aluminium reacts with 3 moles of iron oxide, then, 4 moles of aluminium oxide and 9 moles of iron is formed.

Module 03

1. Which of the following is not a type of rolling mill?
a) Two-high rolling mill
b) Cluster rolling mill
c) Separation rolling mill
d) Tandem rolling mill
Answer: c
Explanation: Among two-high rolling mill, cluster rolling mill, separation rolling mill and tandem rolling mill. Separation rolling mill is not a type of rolling mills.

2. In two high rolling mill, what is the direction of rolling of the two rollers?
a) Clockwise-anticlockwise
b) Clockwise-clockwise
c) Anticlockwise-Anticlockwise
d) Stationery-clockwise
Answer: a
Explanation: In two high rolling mill, the direction of both the rollers is opposite to one another. Hence, one clockwise while other anti-clockwise.

3. In two high rolling mill, if the direction of the rollers is reversed, what is it called?
a) Two high backward mill
b) Two high beneath mill
c) Two high reversing mill
d) Two high anti mill
Answer: c
Explanation: In two high rolling mill, if the direction of the roller is reversed, then that system is called as, two high reversing mill.

4. In three high rolling mill, what is the direction of rolling of the three rollers?
a) Clockwise-clockwise- clockwise
b) Clockwise-anticlockwise- anticlockwise
c) Clockwise-anticlockwise- clockwise
d) Anticlockwise-anticlockwise-anti clockwise
Answer: c
Explanation: In three high rolling mill, the direction of the rollers in the top and bottom are the same, and the direction of the roller in the middle is opposite to the two.

5. How many rollers are used in four high rolling mill?
a) 3
b) 4
c) 8
d) 14
Answer: b
Explanation: In four high rolling mill, there are four rolls employed for roliing. The direction of two rollers is the same and the remaining two rollers roll in opposite directions.

6. The desired shape and cross section of the billet is achieved in one pass.
a) True
b) False
Answer: b
Explanation: The shape and the cross section shape of the billet, which is desired is not obtained in one single pass. One may have to use multiple pass to achieve desired cross section shape.

7. Which of the following property does not improve in the hot rolling process, of a cast?
a) Ductility
b) Shock resistance
c) Toughness
d) Boiling point
Answer: d
Explanation: When a rolled stack is made, there is an improvement seen in the physical properties of the material, it does not affect the boiling point of the material.

8. Which of the following articles cannot be made from rolling?
a) Rails
b) Helmets
c) Bars
d) Plates
Answer: b
Explanation: Rolling is very useful for making articles like bars, plates and rails, but it cannot be used for making helmets. For making helmets, different methods of casting are used.

9. Before beginning the process, the ingots are heated up to what temperature?
a) 1000°C
b) 1200°C
c) 1400°C
d) 1600°C
Answer: b
Explanation: The material ingot is known for sustaining high temperature and heat conditions. Before the process begins, the ingot is fired using gas and brought up to a temperature of 1200°C.

10. In hot rolling process, velocity of material at exit is lowest.
a) True
b) False
Answer: b
Explanation: In hot rolling process, the velocity of material at entry is lower than the velocity at exit.

11. During rolling process, the thickness of workpiece squeezed is called what?
a) Shaft
b) Bore
c) Draft
d) Core
Answer: c
Explanation: During rolling process, the workpiece gets squeezed, causing the thickness of the workpiece to reduce. This reduced thickness is called a draft.

12. With an increase in starting thickness, how would it affect the reduction?
a) Increases
b) Decreases
c) Won’t change
d) Not related
Answer: b
Explanation: When the starting thickness of the workpiece gets increased, the reduction of correspondingly gets decreased.

13. How is the draft calculated?
a) Difference between starting and final thickness
b) Sum of starting and final thickness
c) Product of starting and final thickness
d) Ratio of starting and final thickness
Answer: a
Explanation: Draft is calculated as, the difference between the starting thickness of the workpiece and the final thickness of the workpiece.

14. Which of the following has the most magnitude?
a) Slip velocity
b) Surface velocity
c) Entering velocity
d) Exiting velocity
Answer: d
Explanation: Exiting velocity, among the given four velocities, that is slip velocity, surface velocity, entering velocity and exiting velocity, the exiting velocity is considered to be having most magnitude.

15. Which of the following has least magnitude?
a) Slip velocity
b) Surface velocity
c) Entering velocity
d) Exiting velocity
Answer: c
Explanation: None.

16. When a metal is entering, how are the width and the length of the workpiece related to each other?
a) Direct relation
b) Inverse relation
c) Exponential relation
d) No relation
Answer: b
Explanation: When the metal is entering, the width of the metal is inversely proportional to the length of the workpiece, that is, with an increase in the width of the metal, there would be a decrease in the length of the workpiece and vice versa.

17. Roll velocity is lesser than exiting velocity.
a) True
b) False
Answer: a
Explanation: Exiting velocity is has the most magnitude when compared to the other velocities, and is higher than the roll velocity.

18. When a material is being rolled, the perpendicular force on the arc is called what?
a) Thickness force
b) Roll force
c) Angle force
d) Die force
Answer: b
Explanation: There is a force perpendicular to the arc which is in contact when the rolls are pressurizing the material. This force is called a roll force.

19. How would the draft be affected, if the radius of the roller is decreased?
a) Increase
b) Decrease
c) Won’t change
d) Not related
Answer: b
Explanation: Radius of the roller is directly related with the draft. Hence, with a decrease in the roller radius, there is a decrease in the draft value and vice versa.

20. There is no slipping between roller and workpiece.
a) True
b) False
Answer: a
Explanation: There is a certain amount of slipping that is observed, between the roller and the workpiece. The magnitude of slipping is measured by the term called Forward slip.

21. Blanking is an operation in which the desired part is the sheet left out after making a punch hole in it.
a) True
b) False
Answer: b
Explanation: Blanking is a kind of shearing operation which is generally carried out along a closed contour. In this operation, the required part is the material inside the sheared contour which is called as blank. For example, circular blanks are taken out from the metal sheet for subsequent deep drawing of cups.

22. Die punch clearance is generally very critical for blanking as well as for punching operation.
a) True
b) False
Answer: a
Explanation: Punching is basically a kind of shearing operation in which the required part is the sheet left out after making a punch hole in the metal sheet. This method is also known as contour shearing. Die punch clearance is generally very critical for blanking as well as for punching operation, as it maintains the kind of finish obtained on the final part.

23. In blanking operation, the clearance is provided on the die for obtaining the blank from metal sheet.
a) True
b) False
Answer: b
Explanation: In the blanking or punching operation, the punch diameter should be smaller than the die hole. The clearance between the die and the punch basically depends on the type of process used. For example, for blanking operation, the clearance is provided on the punch for obtaining the blank from metal sheet.

24. Fine blanking is a finishing operation in which shearing is done with very small clearances.
a) True
b) False
Answer: a
Explanation: Fine blanking is normally a single step finishing operation in which shearing is done with very small clearances nearly about one percent. Close tolerances are provided in order to achieve dimensional accuracy in the operation. In this process, smooth edges are produced by the application of clamping force on the blank which also avoids the distortion of sheet during operation.

25. Which of the following parts is used for holding the metal sheet during blanking operation?
a) Spherical steel ball
b) Roller
c) Pressure pad
d) Magnet
Answer: c
Explanation: A pressure pad or a hold down ring with v-shaped projection is used for holding the metal sheet tightly during the blanking operation. This pressure pad is mainly used at the bottom side of the metal sheet. A triple action press, punch and pressure pad are the main equipment used for the blanking operation.

26. Which of the following represents the approximate percentage of metal loss during the blanking operation?
a) 2%
b) 5%
c) 10%
d) 30%
Answer: d
Explanation: In the blanking operation, the material loss is approximately 30 % of the metal sheet used in the cutting off operations. To reduce the waste or metal loss, the shapes to be cut are arranged on the metal sheet properly, this process of reducing metal loss is called as nesting. Nowadays, CAD software is used for this purpose.

27. A power press machine is used in the blanking operation through which a punch is attached.
a) True
b) False
Answer: a
Explanation: In the blanking operation, the main function of the punch is to strike the metal sheet, which is attached to the hub of the power press machine. The striking power is mainly dependent on the capacity of machine used. The punch is attached through the machine by means of tapering at its top locked by a nut.

28. Forming dies are generally used in the blanking and piercing operations.
a) True
b) False
Answer: b
Explanation: Forming dies are used for changing the shape of the blank without removing any material. For example, drawing dies and bending dies are forming dies. For blanking and piercing operations, cutting dies are used to cut the metal from the metal sheet. They basically use cutting and shearing action for cutting the material.

29. Progressive die is a die which can perform two or more operations in a single stroke.
a) True
b) False
Answer: a
Explanation: Progressive die is also called a follow on die. It can perform two or more operations in a single stroke of a ram. Normally, the first operation is punching which is then followed by the blanking operation. The metal sheet is transferred to the next place in between the stroke to form a complete specimen.

30. Which of the following dies is not the type of cutting dies in the metal cutting operations?
a) Squeezing dies
b) Blanking dies
c) Piercing dies
d) Notching dies
Answer: a
Explanation: Blanking dies, piercing dies and notching dies are widely used in the metal cutting operations. But the squeezing die is a type of forming die which is used for performing metal forming operations. In metal forming, drawing dies and bending dies are also used for the forming of metal sheets.

31. Extrusion process is not suitable for which of the following?
a) Steel alloys
b) Non-ferrous alloys
c) Stainless steel
d) Iron
Answer: d
Explanation: Extrusion process is not suitable for any of the iron alloys, neither is it suitable for iron metal. For extruding stainless steel or other non-ferrous alloys or steel alloys, extrusion process can be used.

32. Which of the following is not made using extrusion?
a) Window frames
b) Doors
c) Helmets
d) Rods
Answer: c
Explanation: Among the following, helmets are not manufactured using extrusion, whereas all other products can be manufactured using extrusion.

33. What is the shape of the billet used in extrusion process?
a) Cubical
b) Spherical
c) Cylindrical
d) Pyramidal
Answer: c
Explanation: The shape of the billet in an extrusion process is designed to be cylindrical only. A cubical or spherical or a pyramidal billet cannot be designed for a good output.

34. Which of the following is also called as forward hot extrusion?
a) Direct extrusion
b) Indirect extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer: a
Explanation: Direct extrusion is also called as forward hot extrusion. This method is most widely used and maximum production is done by this method in extrusion.

35. Backward extrusion is another name for which of the following?
a) Direct extrusion
b) Indirect extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer: b
Explanation: Direct extrusion is also called as backward extrusion. In this method, the metal is extruded back into the plunger.

36. In which of the following operations is a dummy block used?
a) Indirect extrusion
b) Direct extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer: b
Explanation: In direct extrusion or forward extrusion, a dummy block is used during the functioning of the extrusion process.

37. Indirect extrusion needs a large amount of force for functioning.
a) True
b) False
Answer: b
Explanation: Indirect extrusion or backward extrusion does not require a large amount of force for operation, as the billet is stationery.

38. Up to what size can wires can be drawn by wire drawing process?
a) 0.01mm
b) 0.02mm
c) 0.03mm
d) 0.04mm
Answer: c
Explanation: It may be counted among one of the limitations of drawing process, that very thin wires can only be drawn from it. In wire drawing process, wires can be drawn up to the size of 0.03mm.

39. Which of the following metal is used in the wire drawing process in die making?
a) Copper
b) Iron
c) Tungsten
d) Magnesium
Answer: c
Explanation: For making dies in the wire extrusion process, copper or iron or magnesium cannot be used, but the compound tungsten carbide is used.

40. A solid ram is used in direct extrusion.
a) True
b) False
Answer: a
Explanation: A solid ram is used in direct extrusion or forward extrusion, whereas a hollow ram is used in indirect extrusion.

41. In which of the following processes most noise is produced?
a) Press forging
b) Drop forging
c) Open die forging
d) Closed die forging
Answer: b
Explanation: Among the following processes, that is press forging, drop forging, open die forging and closed die forging, drop forging is a process where more amount of noise occurs.

42. In which of the following processes most vibration is produced?
a) Press forging
b) Drop forging
c) Open die forging
d) Closed die forging
Answer: b
Explanation: None.

43. Which of the following hammers is also called a gravity hammer?
a) Board hammer
b) Air-lift hammer
c) Power drop hammer
d) Nail hammer
Answer: a
Explanation: Among the following type of drop hammers, that is, board hammer, air-lift hammer, power drop hammer and nail hammer, board hammer is also called a gravity hammer.

44. Which of the following hammers is also called a steam hammer?
a) Board hammer
b) Air-lift hammer
c) Power drop hammer
d) Nail hammer
Answer: c
Explanation: None.

45. Drop forging is the most accurate form of forging.
a) True
b) False
Answer: b
Explanation: It has been observed that press forging is a process which works more smoothly and is lot more accurate than drop forging.

46. In drop forging, the anvil is lighter than the hammer.
a) True
b) False
Answer: b
Explanation: In drop forging, the anvil is a lot heavier than the hammer. To absorb the blow caused by the hammer, the anvil is made 20 times heavier than the hammer.

47. In which of the following processes, life of dies is less?
a) Hot forging
b) Cold forging
c) Drop forging
d) Open die forging
Answer: c
Explanation: In drop forging method, the forging is produced when there is a drop of the hammer on the metal. This causes the life of the hammer and the dies to be less.

48. How much do the presses in press forging weigh?
a) 200-300 tonnes
b) 300-400 tonnes
c) 400-500 tonnes
d) 500-600 tonnes
Answer: d
Explanation: The presses used for such forging processes are manufactured for very heavy use. The presses which are generally used in press forging are of the capacity of 500 to 600 tonnes.

49. Which of the following method is used for making wheel discs?
a) Drop forging
b) Press forging
c) Open die forging
d) Closed die forging
Answer: b
Explanation: Among the following methods, press forging is one method that is the most widely and commonly used method for the manufacture of hollow bodies, wheel discs and panels.

50. Which of the following method is used for making crankshafts?
a) Drop forging
b) Press forging
c) Open die forging
d) Closed die forging
Answer: a
Explanation: For the making of products like car axles, crankshafts, leaf springs and jet turbines, the method of drop forging is used.

Module 04

1. Which kind of resistance is experienced in upset butt welding?
a) Electric resistance
b) Magnetic resistance
c) Thermal resistance
d) Air resistance
Answer: a
Explanation: In the making of an upset butt welding, there are jaws made of copper, into which the part to be welded is put, and hence a solid contact is made. At this point of contact, while the current flows, it gets transformed into heat because of electric resistance.

2. Which of the following can be easily be welded from flash butt welding process?
a) Tin
b) Lead
c) Cast irons
d) Carbon steel
Answer: d
Explanation: In flash butt welding process, the welding of materials like steels and other iron alloys are easy to weld, except for cast iron. The welding of materials like tin, lead, zinc and antimony cannot be welded using flash butt method.

3. Electrodes used in spot welding are made up of which material?
a) Only Copper
b) Copper and tungsten
c) Copper and chromium
d) Copper and aluminium
Answer: d
Explanation: The electrodes that are employed in the spot welding are required to possess a high amount of electrical and thermal conductivity. Hence, they are primarily made up of copper or copper and tungsten or copper and chromium.

4. How are the metals to be welded connected to each other in spot welding?
a) Electric contact
b) Magnetic field
c) Mechanical pressure
d) Direct contact
Answer: c
Explanation: In spot welding process, the metal or the alloy parts which are to be welded, are heated in their in their zones. To bring these parts in contact with one another, mechanical pressure is applied, causing them to connect.

5. Which of the following method is not used in applying pressure in spot welding process?
a) Hand lever
b) Foot lever
c) Air pressure
d) Hydraulic cylinder
Answer: a
Explanation: None.

6. Up to what thickness, can steel be welded using spot welding process?
a) 10 mm
b) 11 mm
c) 12 mm
d) 13 mm
Answer: c
Explanation: In spot welding process, to bring the heated parts in contact with one another, mechanical pressure is applied. This pressure can be of three types, by using foot lever, by providing air pressure or by using a hydraulic cylinder. The use of these methods allows steel or other metal parts to be welded up to a thickness of 12 mm.

7. What is the maximum power supply needed for the working of spot welding process?
a) 135 kVA
b) 140 kVA
c) 145 kVA
d) 150 kVA
Answer: d
Explanation: Spot welding can be used for all types of ductile metals. It can also be employed for structures of sheet metals, and can be applied for making of boxes and cans. For its applications, the maximum power that can be needed for this process is 150 kVA.

8. What is the minimum power supply needed for the working of spot welding process?
a) 10 kVA
b) 14 kVA
c) 6 kVA
d) 22 kVA
Answer: a
Explanation: None.

9. Upset butt welding is majorly used in the making of automobile parts.
a) True
b) False
Answer: b
Explanation: Upset butt welding is mainly used for the manufacture of welding bars, rods, wires or tubing. For the manufacture of automobile parts, such as axles, wheels or frames, flash butt welding is extensively used.

10. In flash butt welding, the forced out metal is called flash.
a) True
b) False
Answer: a
Explanation: In flash butt welding process, there is a light contact between the edges. A high voltage is supplied when the flashing action takes place. In this process, the metal that is forced out, is called as flash.

11. What is the minimum pressure required in a compression molding process?
a) 0.5 MPa
b) 1 MPa
c) 1.5 MPa
d) 2 MPa
Answer: a
Explanation: Processing of thermosetting plastics is classified as, compression molding and transfer molding. The minimum pressure that is required for the complete operation of compression molding is 0.5 MPa.

12. What is the minimum temperature required in a compression molding process?
a) 120°C
b) 125°C
c) 130°C
d) 135°C
Answer: b
Explanation: None.

13. What is the maximum pressure required in a compression molding process?
a) 35 MPa
b) 40 MPa
c) 45 MPa
d) 50 MPa
Answer: d
Explanation: The maximum pressure that is required for the complete operation of compression molding is 50 MPa.

14. What is the maximum temperature required in a compression molding process?
a) 240°C
b) 245°C
c) 250°C
d) 255°C
Answer: c
Explanation: Processing of thermosetting plastics is classified as, compression molding and transfer molding. The maximum temperature that is required for the complete operation of compression molding is 250°C.

15. In compression molding, the curing time does not depend on which of the following factors?
a) Material
b) Curing temperature
c) Geometry
d) Thickness
Answer: b
Explanation: When there has to be molding done for thermosetting materials, mainly compression molding is preferred. While doing this, curing has to be done. The time needed for curing depends on the material used, geometry and thickness of the material.

16. What is the maximum curing time required in a compression molding process?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: d
Explanation: The maximum curing time that is required for the complete operation of compression molding is 5 minutes.

17. What is the minimum curing time required in a compression molding process?
a) 0.4 minutes
b) 0.5 minutes
c) 0.6 minutes
d) 0.7 minutes
Answer: b
Explanation: The minimum curing time that is required for the complete operation of compression molding is 0.5 minutes.

18. What is the maximum pressure required in a transfer molding process?
a) 80 MPa
b) 90 MPa
c) 100 MPa
d) 120 MPa
Answer: c
Explanation: Processing of thermosetting plastics is classified as, compression molding and transfer molding. The maximum pressure that is required for the complete operation of transfer molding is 100 MPa.

19. What is the minimum pressure required in a transfer molding process?
a) 20 MPa
b) 40 MPa
c) 50 MPa
d) 70 MPa
Answer: a
Explanation: The maximum pressure that is required for the complete operation of transfer molding is 20 MPa.

20. Speed of production in transfer molding is higher than that of compression molding?
a) True
b) False
Answer: a
Explanation: It is counted among one of the advantages of transfer molding over compression molding that the speed of production is quite higher. Not just that, but the maintenance in transfer molding too is lower than compression molding.

21. Which of the following processes of moulding is widely used for the manufacturing of bottle caps and automotive dashboards?
a) Compression moulding
b) Transfer moulding
c) Injection moulding
d) Jet moulding
Answer: c
Explanation: Injection moulding is a manufacturing process which uses thermoplastic and thermosetting plastic materials to make products like bottle caps, automotive dashboard, combs etc. In this process, material is fed into a barrel of high temperature, then by mixing it is forced into a mould cavity where it solidifies and gets hardened.

22. Complex shape of parts or components cannot be formed by the injection moulding process.
a) True
b) False
Answer: b
Explanation: Injection moulding is a most common and dominant of all the other plastic processing methods. The process of injection moulding is very versatile and can produce very complex shaped components with the application of multisided moulds. In this process, even components with metal inserts can also be produced.

23. Components from injection moulding process are made very expensive due to the application of very costly equipment.
a) True
b) False
Answer: b
Explanation: In injection molding process, dies are costly to produce parts; the dies can be used to form thousands of parts at very faster rate, so that cost of components reduces that implies this method is very economical for large scale production which can produce any simple or complex products in abundant amount.

24. The three mould technique is generally preferred than the two mould technique in injection moulding process.
a) True
b) False
Answer: a
Explanation: The design in three mould technique has some advantages that it allows more even distribution of melt into the sides of mould cavity. And also provides more automation to the moulding process in comparison with two mould technique. So, the three mould technique is always preferred than the two mould technique in injection moulding process.

25. Which of the following cooling systems is used in injection moulding process to increase solidification rate of components made?
a) Air jet cooling system
b) Water cooling system
c) Cooling with free convection
d) Cooling with fins
Answer: b
Explanation: The cooling system is made by including some passages in the mould walls that are usually connected to an external pump. Cool water is circulated through the passages to extract heat from the hot polymers or plastics components made in the injection moulding process. This cooling system increases the solidification rate which basically reduces the production time.

26. The moulding directions in injection moulding can affect the cost of equipments used in the process.
a) True
b) False
Answer: a
Explanation: The moulding directions involved in injection moulding process basically determines number of cams or inserts which to be used in the process. And if the number of inserts used is more, then the cost involvement will also be more. The moulding is always made in such a way to optimize number of cams as well as the cost.

27. The flow of plastic in the mould cavity is more proper and smooth if the thickness of the component made is very small.
a) True
b) False
Answer: b
Explanation: In injection moulding process, if the component thickness is very small, then the plastic flow is prevented due to high friction. The flow can also be restricted if the gate is very far away from the features of the geometry, or a obstruction in path of flow may also result in prevention of flow.

28. Shrinkage of the plastic parts in mould cavity can results in generation of sink holes in the plastic.
a) True
b) False
Answer: a
Explanation: Shrinking of plastic in mould cavity can result sink holes which are a type of defect that can ruin the product. To avoid such defects, cross-sectional thickness should be maintained uniformly throughout the component. And ribs and gussets must be used which provides mechanical strength to the parts made in the mould.

29. A heavy surface finishing is always required for components made in injection moulding machine.
a) True
b) False
Answer: b
Explanation: Injection moulding is very advantageous when it needs to manufacture intricate parts in abundant quantity. In injection moulding machine, components are often moulded directly in the machine with surface finish and other features like color thereby excluding the secondary finish, which also excludes the cost of further machining.

30. In injection moulding process, ribs are generally provided for the reinforcement to avoid sink marks from the component.
a) True
b) False
Answer: a
Explanation: In order to have reinforcement, ribs can be used which mainly avoid the problem of marks formed on the parts. Reinforcing ribs are generally provided perpendicular to the parting line and made thinner than the mould walls. It is always recommended that the thickness of the ribs should lie between 40% and 60% of wall thickness.

31. Which of the following material is not used in extrusion?
a) Wax
b) Granules
c) Powder
d) Pellets
Answer: a
Explanation: Extrusion is a process of forcing plastic which is at a very high temperature, through the dies, and gets opened at a required shape. The raw materials used for extrusion with polymers contain granules, powder and thermoplastic pellets.

32. In extrusion process, extra shearing occurs in which part of the system?
a) Feed section
b) Pumping section
c) Collapse section
d) Transition section
Answer: b
Explanation: The section where an additional amount of melting and shearing occurs is called a pumping section.

33. Melting section is another name for which section?
a) Feed section
b) Transition section
c) Pumping section
d) Collapse section
Answer: b
Explanation: Melting section is one of the types of extrusion in polymers. Extrusion is a process of forcing plastic which is at a very high temperature, through the dies, and gets opened at a required shape. Melting section is another name for transition section.

34. How are extruded materials cooled?
a) Water
b) Contact with chilled surface
c) Air
d) Oil
Answer: d
Explanation: On completion of extrusion, the material is very hot and has to be cooled down. There are various agents which are used cooling these materials down, such as, air or water or its direct contact with a very cold surface.

35. Which of the following is not an important factor of cooling in extrusion?
a) Reduction in shrinkage
b) Reduction in distortion
c) Ease of adding colours
d) Rate of cooling
Answer: c
Explanation: There are various factors of cooling, a few of them are, reduction in shrinkage, reduction in distortion and the rate of cooling too has to be considered.

36. Which of the following is not an application of polymer extrusion?
a) Door insulation seals
b) Chewing gums
c) Cables
d) Circuit boards
Answer: d
Explanation: Circuit boards is not an application of polymer extrusion. Door insulation seals, chewing gums and cables are the applications of polymer extrusion.

37. Film extrusion process, best involves film having a thickness below what length?
a) 0.2 mm
b) 0.3 mm
c) 0.4 mm
d) 0.5 mm
Answer: d
Explanation: Extrusion of films is one of the most important processes in extrusion. For the films having a thickness below 0.5 mm, these films are best suited for extrusion and can be further applied for making various bags.

38. In the cable extrusion process, what is the speed of product winding?
a) 40 m/sec
b) 50 m/sec
c) 60 m/sec
d) 70 m/sec
Answer: b
Explanation: For the insulation purpose, the coating of any wire or cable is one of the most vital polymer extrusion process. The wire is cooled and then it is wound to large spools at a speed of 50 meters per second.

39. Calendering is mostly suited for making PVC.
a) True
b) False
Answer: a
Explanation: Calendering process is considered to be one of the most important sheet forming process. Calendering has many products like phenyl, cellulose or vinyl floor tiles. It is most suited for making PVCs.

40. Tubes having U shape cannot be manufactured by polymer extrusion process.
a) True
b) False
Answer: b
Explanation: Polymer extrusion has a variety of applications such as candy canes, chewing gums, window frames, solid rods, pipes or tubes having U or J sections.

Module 05

1. Which machine tool is known as the mother machine tool?
a) drill
b) milling
c) lathe
d) none of mentioned
Answer: c
Explanation: Lathe is known as the mother machine tool because it
can perform various type of operations. It is a versatile machine.

2. Lathe is primarily used for producing ____surfaces.
a) flat
b) curve
c) taper
d) none of the mentioned
Answer: d
Explanation: Lathe is primarily used for producing cylindrical surfaces. But today it can perform various operations and perform various surfaces like curvilinear surface, flat surface and so on.

3. Which type of surface is produced by turning operation in lathe machine?
a) flat
b) cylindrical
c) taper
d) none of the mentioned
Answer: b
Explanation: Cylindrical surface is produced by turning operation in lathe machine. This turning can be done on the external surface. Boring is a type of turning which is performed in the internal surface.

4. What is the necessary condition for turning?
a) material of work piece should be harder than the cutting tool
b) cutting tool should be harder than the material of work piece
c) hardness of the cutting tool and material of of piece should be same
d) none of the mentioned
Answer: b
Explanation: Cutting tool should be harder than the material of work piece, so that it can be able to cut the work piece into the desire shape.

5. Traversing of tool parallel to the axis of job is termed as_____
a) cross feed
b) longitudinal feed
c) both cross feed and traversing feed
d) none of the mentioned
Answer: b
Explanation: It is the definition of longitudinal feed. Similarly, traversing of tool perpendicular to the axis of job is known as cross feed.

6. The swing diameter over the bed is the largest diameter.
a) true
b) false
Answer: a
Explanation: This is true. Swing diameter over the lathe is the largest diameter of work over the bed that will revolve without touching height of the centres measured from the bed of the lathe.

7. Lathe cannot produce internal features like holes.
a) true
b) false
Answer: b
Explanation: This is false. Lathe is a versatile machine tool. It can produce holes, flat surfaces and so on.

8. Which type of feed is needed in facing operation?
a) longitudinal
b) cross
c) both cross and longitudinal
d) none of the mentioned
Answer: b
Explanation: Facing operation is done by the cross feed. In facing, workpiece is rotated against the single point cutting tool.

9. Which type of surface is produced in facing operation?
a) cylindrical
b) taper
c) flat
d) none of the mentioned
Answer: c
Explanation: Flat surface is produced in facing operation as per the definition. In facing operation, metal is removed by the tool from thee end of the metal and flat surface is produced.

10. Traversing of tool at any angle to the job axis produces curve surfaces.
a) true
b) false
Answer: b
Explanation: This is false. Traversing of tool at any angle to the job axis produces taper surfaces.

11. In taper operation, which type of surface is produced?
a) flat
b) curve
c) circular
d) none of the mentioned
Answer: d
Explanation: Taper type surface is produced in the process of taper turning. Taper is a shape in which the diameter of the both ends of bar are different.

12. Which type of feed is needed in turning operation?
a) longitudinal
b) cross
c) both cross and longitudinal
d) none of the mentioned
Answer: a
Explanation: As per definition, longitudinal feed is needed in turning operation. Longitudinal feed is always parallel to the axis of rotation of the spindle.

13. Which type of surface can be produced by lathe?
a) flat
b) cylindrical
c) curvilinear
d) all of the mentioned
Answer: d
Explanation: Lathe is a versatile machine. It can perform various types of jobs. It is primarily intended for producing only cylindrical surface but it can produce various types of surfaces.

14. Which type of lathe is also known as centre lathe?
a) engine lathe
b) bench lathe
c) room lathe
d) capstan lathe
Answer: a
Explanation: Engine lathe is also known as the centre lathe. This centre lathe is generally used for the production of cylindrical surfaces.

15. Wheel lathe is the type of ____
a) engine lathe
b) centre lathe
c) speed lathe
d) special purpose lathe
Answer: d
Explanation: Wheel lathe is the type of special purpose lathe. This lathe is generally used for the purpose of turning wheels of railways locomotives and so on.

16. Wood working lathe is the type of ____
a) engine lathe
b) centre lathe
c) speed lathe
d) special purpose lathe
Answer: c
Explanation: Wood lathe is the type of speed lathe. Speed lathe can revolve spindle with great speed. It is also used for turning small objects.

17. Geared lathe is the type of____
a) engine lathe
b) centre lathe
c) speed lathe
d) special purpose lathe
Answer: a
Explanation: Geared lathe is the type of engine lathe. Engine lathe is a screw cutting type lathe. It has back-geared cone-driven headstock.

18. Belt driven lathe is the type of____
a) engine lathe
b) centre lathe
c) speed lathe
d) special purpose lathe
Answer: b
Explanation: Belt driven lathe is the type of centre lathe. In practical, various types of belt driven machines are used like V belt driven machine and so on.

19. Duplicating lathe is the type of____
a) engine lathe
b) centre lathe
c) speed lathe
d) special purpose lathe
Answer: d
Explanation: As per the classification of lathe, duplicating lathe the type of special purpose lathe. It is rarely used.

20. Spinning lathe is the type of____
a) engine lathe
b) centre lathe
c) speed lathe
d) special purpose lathe
Answer: c
Explanation: Spinning lathe is the type of speed lathe. Spinning lathe is a lathe generally used the purpose of shaping metal holloware with the help of flat stock over a form (of revolving type) with the help of hand tool.

21. Which of the following is the type of engine lathe?
a) centering lathe
b) individual motor driven lathe
c) duplicating lathe
d) all of the mentioned
Answer: b
Explanation: Centering lathe is the example of speed lathe and duplicating lathe is the type of special purpose lathe while individual motor driven lathe is an example of engine lathe.

22. Which of the following is special purpose lathe?
a) polishing lathe
b) centering lathe
c) spinning lathe
d) none of the mentioned
Answer: d
Explanation: Polishing lathe, centering lathe and spinning lathe are the examples of speed lathe.

23. Which of the following is the example of speed lathe?
a) wheel lathe
b) polishing lathe
c) gap bed lathe
d) all of the mentioned
Answer: b
Explanation: Wheel lathe and gap bed lathe are the examples of the special purpose lathe while polishing lathe is an example of speed lathe.

24. T – lathe is the example of bench lathe.
a) true
b) false
Answer: b
Explanation: This is false. T – lathe is the example of special purpose lathe.

25. Which of the following is the type of lathe?
a) bench lathe
b) tool room lathe
c) capstan and turret lathe
d) all of the mentioned
Answer: d
Explanation: These all are the types of lathe as per the lathe classification. Lathe is primarily intended for the purpose of producing cylindrical surfaces although today it becomes a versatile tool.

26. Lathe can be classified on the basis of_____
a) designs and construction
b) fundamental principle
c) function performance
d) all of the mentioned
Answer: a
Explanation: All types of lathe machine employ the same fundamental principle of operation and perform the same function. They are differ only in the terms of their designs and constructions.

27. Wood working lathe is the example of capstan and turret lathe.
a) true
b) false
Answer: b
Explanation: This is false. Wood working lathe is the example of speed lathe.

Module 06

1. In machining of a workpiece, the material is removed by_____
a) drilling action
b) melting action
c) shearing acting
d) using brittleness of the material
Answer: c
Explanation: There are different machining processes, such as turning, milling, boring etc. In all these cases metal is removed by a shearing process, which occurs due to the relative motion between the workpiece and the tool. Generally, one of the two rotates at designated and generally high speed, causing the shearing of material (known as chips), from the workpiece. The other moves relatively slowly to effect removal of metal throughout the workpiece.

2. The depth that the tool is plunged into the surface is called as ______
a) feed
b) depth of cut
c) depth of tool
d) working depth
Answer: b
Explanation: The depth of cut, DOC is the depth that the tool is plunged into the surface. Feed defines the relative lateral movement between the cutting tool and the workpiece. Thus, together with the depth of cut, feed decides the cross section of the material removed for every rotation of the job or the tool.

3. Feed is measured in units of _____
a) length/revolution
b) degree/revolution
c) length
d) velocity
Answer: a
Explanation: Feed is the amount of material removed for each revolution or per pass of the tool over the workpiece and is measured in units of length/revolution, length/pass or other appropriate units for the particular process.

4. CNC machining centres do not include operations like ______
a) milling
b) boring
c) welding
d) tapping
Answer: c
Explanation: CNC machining centres are developed for machining prismatic components combining operations like milling, drilling, boring and tapping. Gradually machines for manufacturing cylindrical components, called turning centres are also developed.

5. In CNC systems multiple microprocessors and programmable logic controllers work ______
a) in parallel
b) in series
c) one after the other
d) for 80% of the total machining time
Answer: a
Explanation: In CNC systems multiple microprocessors and programmable logic controllers work in parallel for simultaneous servo position and velocity control of several axes of a machine for contour cutting as well as monitoring of the cutting process and the machine tool.

6. Which of the following is not the advantage of CNC machines?
a) Higher flexibility
b) Improved quality
c) Reduced scrap rate
d) Improved strength of the components
Answer: d
Explanation: CNC machines offer the following advantages in manufacturing:
• Higher flexibility
• Increased productivity
• Improved quality
• Reduced scrap rate
• Reliable and Safe operation
• Smaller footprint.

7. In how many ways CNC machine tool systems can be classified?
a) 2
b) 3
c) 4
d) 5
Answer: b
Explanation: CNC machine tool systems can be classified in various ways such as:
• Point-to-point or contouring: depending on whether the machine cuts metal while the workpiece moves relative to the tool
• Incremental or absolute: depending on the type of coordinate system adopted to parameterise the motion commands
• Open-loop or closed-loop: depending on the control system adopted for axis motion control.

8. Point-to-point systems are used for _____
a) reaming
b) parting
c) grooving
d) facing
Answer: a
Explanation: Such systems are used, typically, to perform hole operations such as drilling, boring, reaming, tapping and punching. In a PTP system, the path of the cutting tool and its feed rate while traveling from one point to the next are not significant, since, the tool is not cutting while there is motion.

9. In part programming, interpolation is used for obtaining _______ trajectory.
a) helicoidal
b) pentagonal
c) triangular
d) zig-zag
Answer: a
Explanation: Interpolation consists of the calculation of the coordinated movement of several axes using the programmed parameters, in order to obtain a resulting trajectory, which can be of various types, such as:
– Straight line
– Circular
– Helicoidal.

10. For CNC machining skilled part programmers are needed.
a) True
b) False
Answer: a
Explanation: The main disadvantages of NC systems are:
• Relatively higher cost compared to manual versions
• More complicated maintenance due to the complex nature of the technologies
• Need for skilled part programmers.

11. An absolute NC system is one in which all position coordinates are referred to one fixed origin called the zero point.
a) True
b) False
Answer: a
Explanation: An absolute NC system is one in which all position coordinates are referred to one fixed origin called the zero point. The zero point may be defined at any suitable point within the limits of the machine tool table and can be redefined from time to time.

12. Wrist motion of y involves
a) right to left rotation of the object
b) up and down rotation of the object
c) twisting of the object about the arm axis
d) none of the mentioned
Answer: a
Explanation: Wrist motion always follows right hand rule.

13. Robots are specified by
a) pay load
b) dimension of work envelope
c) degree of freedom
d) all of the mentioned
Answer: d
Explanation: None.

14. Hydraulic drives are used for a robot when
a) high torque is required
b) high power is required
c) rapid motion of robot arm
d) all of the mentioned
Answer: d
Explanation: None.

15. The following type of robot is most suitable for pick and place operations
a) rectangular
b) cylindrical
c) spherical
d) jointed arm type
Answer: a
Explanation: The fixed-sequence robot, also called a pick-and-place robot, is programmed for a specific sequence of operations. Its movements are from point to point, and the cycle is repeated continuously.

16. A computer program that contains expertise in a particular domain is called an
a) automatic processor
b) intelligent planner
c) expert system processor
d) operations symbolizer
Answer: c
Explanation: None.

17. The knowledge base of an expert system includes both facts and
a) theories
b) heuristics
c) algorithms
d) analysis
Answer: b
Explanation: Heuristics is any approach to problem solving, learning, or discovery that employs a practical methodology not guaranteed to be optimal or perfect, but sufficient for the immediate goals.

18. A robot’s arm is also known as its
a) actuator
b) end effector
c) manipulator
d) servomechanism
Answer: c
Explanation: The manipulator is a mechanical unit that provides motions (trajectories) similar to those of a human arm and hand.

19. Which type of actuator generates a good deal of power but tends to be messy?
a) electric
b) hydraulic
c) pneumatic
d) none of the mentioned
Answer: b
Explanation: None.

20. If a robot can alter its own trajectory in response to external conditions, it is considered to be
a) intelligent
b) mobile
c) non servo
d) open loop
Answer: a
Explanation: The intelligent robot, also called a sensory robot, is capable of performing some of the functions and tasks carried out by humans. It is equipped with a variety of sensors with visual (computer vision) and tactile capabilities.

21. Programming a robot by physically moving it through the trajectory you want it to follow is called
a) contact sensing control
b) continuous path control
c) pick and place control
d) robot vision control
Answer: b
Explanation: None.

22. Reasoning from a goal state towards an initial state is called
a) backward chaining
b) bidirectional
c) breadth first
d) heuristic
Answer: a
Explanation: Heuristics is any approach to problem solving, learning, or discovery that employs a practical methodology not guaranteed to be optimal or perfect, but sufficient for the immediate goals.

23. Which device is mostly associated with automation?
a) flexible manufacturing
b) robots
c) computer graphics workstation
d) NC machine
Answer: b
Explanation: Only robots are associated with automation.

24. Choose the basic element for an automated machine tool
a) logic
b) NC tape programming
c) software
d) workstation
Answer: a
Explanation: None.

25. Choose the robot component from the following
a) micro computer
b) coaxial cable
c) arm
d) software
Answer: c
Explanation: Arm is the major component of a robot.

26. A configuration for a robot is
a) octagonal
b) oblong
c) square
d) spherical
Answer: d
Explanation: None.

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