## [MCQ’s]Automobile Engineering

#### Module 01

1. If there are 7 clutch plates in a multi-plate clutch, what is the number of pair of contact surfaces?
a) 5
b) 4
c) 6
d) 8
Explanation: If ‘n’ is the no. of clutch plates in a multi-plate clutch, then, number of pairs of contact surfaces = ‘n-1’. Therefore no. clutches plates = 7 – 1 = 6.

2. External diameter of the clutch facing is limited to 120 mm and the inner diameter may be assumed to be 0.3 times the external diameter. Assume uniform wear theory. What is the effective mean radius?
a) 68
b) 58
c) 98
d) 78
Explanation: External diameter = 120 mm. Given Internal diameter = 0.3*external diameter = 0.3 * 120 = 36 mm. Effective mean diameter = (120 + 36) / 2 = 78 mm ⇒ Effective mean radius = 39 mm.

3. The clutch plate has 160 mm inside and 240 mm outside diameter. The total force provided by the springs is 5 kN, when the clutch is new. The coefficient of friction is 0.4. What is the torque transmitted?
a) 300 Nm
b) 350 Nm
c) 400 Nm
d) 450 Nm
Explanation: inside radius = 80 mm, outside radius = 120 mm ⇒ Effective mean radius = R = (80 + 120) / 2 = 100 mm. Let W = 5 kN = 5000 N and μ = coefficient of friction = 0.4. Torque transmitted = 2 * μ * W * R = 2 * 0.4 * 5000 * 100 = 400 * 103 Nmm = 400 Nm.

4. Which of the following contains no linkage between the clutch and the pedal?
a) Clutch – by – wire
b) Wet clutch
c) Hydraulic single plate clutch
d) Hydraulic multi-plate clutch
Explanation: In clutch – by – wire system, there is no mechanical linkage between the clutch and the pedal. The ECU and the actuator control the clutch pedal.

5. Where is the clutch located?
a) Between transmission and engine
b) Between transmission and rear axle
c) Between transmission and propeller shaft
d) Between transmission and differential
Explanation: The clutch is in the middle of transmission and engine. So that torque can be transmitted from engine to the transmission whenever required.

6. Which of the following parts of the cover assembly that hold the pressure plate against the clutch plate?
a) Springs
b) Thrust bearings
c) Struts
d) Lever
Explanation: Springs hold the pressure plate against the clutch plate so that pressure can be exerted against the clutch plate and better power transmission can be obtained.

7. Which of the following is the coefficient of friction of the clutch plate?
a) 1.3
b) 0.8
c) 0.4
d) 0.1
Explanation: The coefficient of friction is always less than 1. Most commonly used material for the clutch plate is ceramic in case of racing cars, heavy loads, etc.

8. Which of the following is the disadvantage of the cone clutch?
a) It becomes difficult to disengage the clutch when the cone angle is less than 20°
b) It is silent in operation
c) The normal force on the contact surface is larger than the axial force
d) Same torque can be transmitted for the same size as the plate clutch
Explanation: When the cone angle of the cone clutch is less than 20° than the male part of the clutch join the female part and it difficult to disengage the clutch.

9. The external radius of the cone clutch is 120 mm and the internal radius is 80 mm. The cone angle is kept at 20°. What is the effective mean radius assuming the uniform wear theory?
a) 292 mm
b) 295 mm
c) 100 mm
d) 150 mm
Explanation: ri = 80 mm, r0 = 120 mm and θ = 20°. Effective mean radius = (ri + ro) / (2*Sin(θ)) = (80 + 120) / (2 * Sin(20°)) = 292.3 mm.

10. The dry clutch can tolerate longer engagement time than a wet clutch.
a) True
b) False
Explanation: Since metal to oil heat transfer is more effective than the metal to the air, the wet clutch acts as a much better heat exchanger and wet clutch can tolerate longer engagement time.

11. Which of the following is the need of the gearbox?
a) To vary the speed of the vehicle
b) To vary the torque of the vehicle
c) To vary the power of the vehicle
d) To vary the acceleration of the vehicle
Explanation: The purpose of the gearbox is to give means so that the torque can be varied as required between the engine and the road wheels.

12. In which type of manual transmission the double-declutching is used?
a) Constant-mesh gearbox
b) Sliding mesh gearbox
c) Synchromesh gearbox
d) Epicyclical gearbox
Explanation: The double-declutching is used in the constant-mesh gearbox. For the smooth engagement of the dog clutch, the speed of the main shaft and layshaft should be the same.

13. In which of the gearbox all gears are always in contact?
a) Constant-mesh gearbox
b) Sliding mesh gearbox
c) Synchromesh gearbox
d) Epicyclical gearbox
Explanation: In constant mesh gearbox, all gears on the layshaft and main shaft are in contact all the time. For selecting gear, the dog clutch is used.

14. In which of the gearbox sun and planet gear set is used?
a) Constant-mesh gearbox
b) Sliding mesh gearbox
c) Synchromesh gearbox
d) Epicyclical gearbox
Explanation: In epicyclic gearbox, the sun and planet gears are used. Using this arrangement various gear ratios can be obtained. Also, this type of gearbox is compact in design than other types of gearbox.

15. Where is the overdrive located?
a) Between transmission and engine
b) Between transmission and rear axle
c) Between transmission and propeller shaft
d) Between transmission and differential
Explanation: The overdrive is used to increase the gear ratio of the vehicle. It used where the high speed is needed at relatively low engine speed. By using overdrive, the wear of the engine parts is less and decreases the vibration and noise.

16. Which of the following is not part of automatic transmission?
a) Epicyclic gearbox
b) Torque convertor
c) Multi-plate clutch
d) Sliding mesh gearbox
Explanation: The automatic transmission consists of the epicyclic gearbox, torque convertor, and multi-plate clutch. The sliding mesh gearbox is a type of manual transmission.

17. In which of the configuration of epicyclic gearbox output will be forward and fast output speed?
a) Sun gear stationary, ring gear driven, planet carrier driving
b) Sun gear driving, ring gear driven, planet carrier stationary
c) Sun gear driven, ring gear stationary, planet carrier driving
d) Sun gear stationary, ring gear stationary, planet carrier driving
Explanation: When the Sun gear is stationary, the planet carrier is driving and the ring gear is driven then output is forward and fast speed. When any two of the three are stationary then we get the direct drive.

18. Which types of gears are used in constant mesh gearbox?
a) Spur gear
b) Helical gear
c) Bevel gear
d) Worm gear
Explanation: As the gears are always in mesh in the constant-mesh gearbox, therefore there is no need for using the spur gears and the helical gears are used as those are quite in use.

19. Why are the helical gears used commonly in transmission over spur gears?
a) Low cost and high strength
b) Low noise level and high strength
c) Low noise level and economy
d) Low noise level and low cost
Explanation: The teeth profile on the helical gear is at an angle to the axis of the gear because of which helical gears produce less noise during operation and also they have high strength.

20. Increase of torque in a vehicle is obtained by decreasing power.
a) True
b) False
Explanation: Increase of torque in a vehicle is obtained by decreasing speed. As we know P = 2πNT/60 for the same power (P), T (torque) is inversely proportional to N (speed).

21. Which types of joints are used when the shafts are inclined?
a) Universal joint
b) Hinge joint
c) Ball and socket joint
d) Pivot joint
Explanation: Universal joint is used when the shafts are inclined and intersecting. It is very compact in design and simple in construction. It is very effective at small angles of propeller shaft movement.

22. The axes of the two shafts are intersecting and are at 25° to each other. These two shafts are connected by Hook’s joint. At which position of the drives shaft velocity ratio will be maximum?
a) 90°, 270°
b) 0°, 180°
c) 180°, 270°
d) 90°, 180°
Explanation: (ωB / ωA) = (cos α) / (1 – cos2θ sin2α) where A = driving shaft and B = driven shaft and α is the angle between shaft A and shaft B. θ is the angle through which the shaft A rotates. Velocity ratio is maximum when θ = nπ where n = 1, 2, 3, …… i.e. θ = θ° or 180°.

23. Which of the following is the disadvantage of the open differential?
a) High in cost
b) Not reliable
c) Complex design
d) Sends most of the power to the wheel having less traction
Explanation: The major disadvantage of the open differential in that it transfers the power to the wheel even if it is on a slippery road. That’s why it is not used in off driving cars.

24. Why do the hypoid gears require special lubricant?
a) Teeth are soft
b) Teeth are hard
c) Gears run faster
d) There is relative motion between teeth
Explanation: Hypoid gears require special lubricant because of the extreme pressure between the teeth. The sliding motion of the teeth is effective due to the use of special lubricant.

25. The axes of the two shafts are intersecting and are at 30° to each other. These two shafts are connected by Hook’s joint. At which position of the drives shaft velocity ratio will be minimum?
a) 90°, 270°
b) 0°, 180°
c) 180°, 270°
d) 90°, 180°
Explanation: (ωB / ωA) = (cos α) / (1 – cos2θ sin2α) where A = driving shaft and B = driven shaft and α is the angle between shaft A and shaft B. θ is the angle through which the shaft A rotates. Velocity ratio is minimum when θ = m&pi/2 where m = 1, 3, 5, …… i.e. θ = 90° or 270°.

26. Where is the differential located?
a) Between transmission and rear axle
b) Between engine and transmission
c) Between two propeller shaft
d) Between steering wheel and steering column
Explanation: The differential used to incorporate the speed of the rear wheels and front wheels during turning. It is located between the transmission and rear axle.

27. The axes of the two shafts are intersecting and are at 35° to each other. These two shafts are connected by Hook’s joint. At which position of the drives shaft velocity ratio will not be unity?
a) 42.145°
b) 222.145°
c) 317.85°
d) 141.52°
Explanation: (ωB / ωA) = (cos α) / (1 – cos2θ sin2α) where A = driving shaft and B = driven shaft and α is the angle between shaft A and shaft B. θ is the angle through which the shaft A rotates. Velocity ratio is unity when tanθ = ± cosα−−−−√=±cos35−−−−−√ = ± 0.90 i.e. θ = 42.145°, 222.145°, 317.85°, and 137.85°.

28. What is the need of the universal joint?
a) To change inclination
b) To bend sideways
c) To transfer torque at an angle
d) To change length
Explanation: The universal joint transfers the torque to two intersecting shafts. One or two universal joints are used depending upon the type of rear-drive used.

29. The axes of the two shafts are intersecting and are at 35° to each other. These two shafts are connected by Hook’s joint. At which position of the drives shaft acceleration will be maximum?
a) 68.4°
b) 96.1°
c) 225.5°
d) 330.7°
Explanation: (ωB / ωA) = (cos α) / (1 – cos2θ sin2α) where A = driving shaft and B = driven shaft and α is the angle between shaft A and shaft B. θ is the angle through which the shaft A rotates. Acceleration will be maximum when cos2θ = (2 sin2α) / (2 – sin2α) =(2 sin240°) / (2 – sin240°) = 0.5207 i.e. 2θ = 58.62 i.e. θ = 29.31°, 180° – 29.31° = 150.69°, 180° + 29.31° = 209.31°, 360° – 29.31° = 330.69°

30. A two-piece propeller shaft requires one universal joint.
a) True
b) False
Explanation: A two-piece propeller shaft requires a center support bearing. If there is a large wheelbase, the long propeller shaft is needed. So a two-piece propeller shaft is used in such case with a center support bearing. By incorporating this there is no sag or whirl.

#### Module 02

1. The front axle of a car has pivot centers 1.3 m apart. The angle of inside lock is 40℃ and the angle of the outside lock is 35℃. What is the wheelbase of the car?
a) 5.5 m
b) 3.5 m
c) 4.5 m
d) 6.5
Explanation: For correct steering, cot α – cot θ = c / b where c = pivot center, b = wheelbase, α = angle of outside lock, and θ = angle of inside lock. Cot α – Cot θ = c / b ⇒ Cot 35 – Cot 40 = 1.3 / b ⇒ b = 5.49 m.

2. If the wheelbase, the pivot center, and wheel track of the are 2.5 m, 1.1 m, and 1.3 m respectively. The angle of the inside lock is 42℃. What is the circle radius of the outer front wheel?
a) 2.6 m
b) 3.6 m
c) 4.6 m
d) 1.6 m
Explanation: b = wheelbase = 2.5 m, c = pivot center = 1.1 m, a = wheel track = 1.3 m, and θ = angle of inside lock = 42℃. For the inner front wheel, radius =bsinθac2=2.5sin421.31.12 = 3.6 m

3. What is the angle between the steering axis and the vertical in the plane of the wheel?
a) Castor
b) Camber
c) Steering axis inclination
d) Kingpin inclination
Explanation: Castor is the angle between the steering axis and the vertical in the plane of the wheel. Positive castor improves the straight-line stability of the car.

4. If the front of the front wheels is inside and rear of front wheels are apart when the vehicle is at rest, then the configuration is called?
a) Toe-in
b) Toe out
c) Positive camber
d) Positive castor
Explanation: Toe-in is the amount by which the front wheels are set closer together at the front than at the rear when the vehicle is stationary. Toe-in provided generally less than 3 mm.

5. What is the name of the angle through which the wheel has to turn to sustain the side force?
a) Slip angle
b) Castor angle
c) Camber
d) Kingpin inclination
Explanation: The slip angle is the angle through which the wheel has to be turned to sustain the side force on the wheel. The force produced due to this which counters the side thrust is known as cornering force.

6. What is called the cornering force over the slip angle?
a) Castor trail
b) Cornering power
c) Self-righting torque
d) Pneumatic trail
Explanation: The ratio of cornering force to the slip angle is called the cornering power. The cornering power increases due to tire stiffness.

7. What is a condition called when the vehicle will try to move away from its normal direction and to keep it on the right path there is need to steer a little?
a) Understeer
b) Oversteer
c) Reversibility
d) Irreversibility
Explanation: When the slip angles of the front wheels are greater than those for the rear wheels, the radius of the turn is increased. Due to which there is the need to steer more than required which is called understeer.

8. What is the purpose of the reciprocating ball type steering gear?
a) To reduce the operating cost
b) To reduce the number of parts
c) To reduce the operating friction
d) To reduce the toe-out during the turns
Explanation: The reciprocating ball type steering gear serve the purpose of reducing the friction and wear of the gear.

9. What is the angle between the vertical when the top of the wheel slants outward?
a) Negative camber
b) Negative castor
c) Positive camber
d) Positive castor
Explanation: The angle between the vertical when the top of the wheel slants outward is called positive camber. Positive camber will lead to decrease in turning radius and thus lead to a decrease in the steering effort.

10. The furniture rollers are provided with negative castor.
a) True
b) False
Explanation: The furniture rollers are provided with positive castor. The positive castor gives more directional stability. In positive castor, steering axis would meet the ground ahead of the center of the roller. The later wheel would always follow the former wheel.

a) Bleed screw
b) Piston
c) Caliper
d) Piston seal
Explanation: Piston seal provides the pad-to-disc adjustment in a disc brake. When the brake is applied, the piston seal deforms.

12. What is the braking torque at leading shoe if resultant frictional force acts at a distance of 250 mm from the brake drum center, coefficient of friction between the shoe and the drum as 0.5, the free ends of the two shoes are pushed apart with a force of 300 N which is acting at a distance of 320 mm from anchor, and two shoes are anchored together 170 mm away from the brake drum center?
a) 276.6 Nm
b) 256.6 Nm
c) 266.6 Nm
d) 246.6 Nm
Explanation: TL =WLμRM(μR)=3203000.5250170(0.5250) = 266666.66 Nmm = 266.6 Nm where L is the distance at which the force acts from the anchor, W is the force from the anchor, μ is the coefficient of friction, R is the distance of resulting friction force from brake drum center, M is the distance between the two anchors.

13. On what principle does the braking system in the car work?
a) Frictional force
b) Gravitational force
c) Magnetic force
d) Electric force
Explanation: Frictional force is the main force which acts and plays an important role in the braking system. The disc pads get to rub against the drum and which creates the friction and opposes the motion of the rotational motion of the drum.

14. Generally which brakes are on the front wheels?
a) Drum brake
b) Disk brake
c) Shoe brake
d) Double shoe brake
Explanation: Disk brakes are used usually on the front wheels. When the brakes are applied the 70% of the weight is transferred to the front wheels. Because of which the brakes on the front wear out faster.

15. If the car is moving on the level road at a speed of 50 km/h has a wheelbase 3 m, a distance of C.G. from ground 700 mm and distance from rear wheels is 1.1 m. Coefficient of friction is 0.7. What is the retardation if the brakes are applied to the rear wheels?
a) 3.7 m/s2
b) 2.7 m/s2
c) 1.7 m/s2
d) 4.7 m/s2
Explanation: When the brakes are applied on the rear wheels and the vehicle is moving on the level road, a = μg(Lx)L+μh where ‘μ’ is the coefficient of friction, ‘L’ is wheelbase, ‘x’ is a distance of C.G. from rear wheels, and ‘h’ is the distance of the C.G. from the surface of the road. Therefore a = 0.79.81(31.1)3+(0.70.7) = 3.7 m/s2.

16. If the car is moving on the level road at a speed of 50 km/h has a wheelbase 4 m, a distance of C.G. from ground 800 mm and distance from rear wheels is 1.2 m. Coefficient of friction is 0.8. What is the retardation if the brakes are applied to the front wheels?
a) 3.4 m/s2
b) 2.4 m/s2
c) 1.4 m/s2
d) 4.4 m/s2
Explanation: When the brakes are applied on the front wheels and the vehicle is moving on the level road, a = μgxLμh where ‘μ’ is the coefficient of friction, ‘L’ is wheelbase, ‘x’ is a distance of C.G. from rear wheels, and ‘h’ is the distance of the C.G. from the surface of the road. Therefore a = 0.79.811.24(0.80.8) = 2.4 m/s2.

17. If the car is moving on the level road at a speed of 50 km/h has a wheelbase 4 m, a distance of C.G. from ground 800 mm and distance from rear wheels is 1.2 m. Coefficient of friction is 0.8. What is the retardation if the brakes are applied to all wheels?
a) 7.8 m/s2
b) 6.8 m/s2
c) 5.8 m/s2
d) 4.8 m/s2
Explanation: When the brakes are applied on all wheels and the vehicle is moving on the level road, a = μ*g where ‘μ’ is the coefficient of friction, ‘L’ is wheelbase, ‘x’ is a distance of C.G. from rear wheels, and ‘h’ is the distance of the C.G. from the surface of the road. Therefore a = 0.8 * 9.81 = 7.8 m/s2.

18. The car is moving up on the 12o inclined road with horizontal at 36 km/h which is having wheelbase 1.4 m. The C.G. of the car is 0.9 m above the road. The coefficient of friction is 0.7. What is the retardation of the car if the brakes are applied to all the four wheels?
a) 8.75 m/s2
b) 8.81 m/s2
c) 7.71 m/s2
d) 6.81 m/s2
Explanation: α is the inclination angle in degree = 12°, μ is the coefficient of friction = 0.7. When the vehicle is moving up on the inclined road and brakes are applied to all four wheels than the retardation a = g*(μ*cosα + sinα) = 9.81*(0.7*cos12° + sin12°) = 8.75 m/s2.

19. The car is moving down on the 14° inclined road with horizontal at 36 km/h which is having wheelbase 1.4 m. The C.G. of the car is 0.9 m above the road. The coefficient of friction is 0.75. What is the retardation of the car if the brakes are applied to all the four wheels?
a) 4.76 m/s2
b) 5.76 m/s2
c) 6.76 m/s2
d) 7.76 m/s2
Explanation: α is the inclination angle in degree = 14° μ is the coefficient of friction = 0.75. When the vehicle is moving down on the inclined road and brakes are applied to all four wheels than the retardation a = g*(μ*cosα – sinα) = 9.81*(0.75*cos14° – sin14°) = 4.76 m/s2.

20. The metering valve is used to proportion the braking effect between the front and the rear axle.
a) True
b) False
Explanation: The proportioning valve is used to proportion the braking effect between the front and the rear axle.

21. In a differential with a gear ratio of 4 : 1 the drive pinion would revolve four times to cause the ring gear to rotate
(a) 1 time
(b) 2 times
(c) 4 times
(d) 6 times

22. More often, the condition that draws attention to trouble in the differential is
(a) Rough operation
(b) Noise
(c) Power loss

23. To correct heavy toe contact on ring gear teeth, move the
(a) Ring gear towards pinion
(b) Ring gear away from pinion
(c) Drive pinion out and back lash

24. On a straight road, the ring gear
(a) Rotates at the same speed as wheels
(b) Rotates faster than wheels
(c) Rotates slower than wheels
(d) Does not rotate

25. In a passenger car a typical arrangement of braking with drum brakes will be
(a) Two leading shoes at front and leading & trailing at rear
(b) All the wheels having leading and trailing shoes
(c) All the wheels having two leading shoes

6. Brake efficiency is a term which denotes
(a) Efficiency of the braking system as a whole
(b) Efficiency of the braking linings
(c) The deceleration as percentage of gravity
(d) Efficiency of the operating linkage

27. The most widely used brakes are operated
(a) Electrically
(b) Hydraulically
(c) By air pressure
(d) By vacuum

28. As a rule when comparing the front and rear wheel cylinder pistons it will be found that the pistons in the
front wheel cylinders are
(a) The same size
(b) Smaller in diameter
(c) Larger in diameter

29. The type of braking system referred to as power brake, makes use of
(a) Electromagnets
(b) Compressed air
(c) Vacuum

30. In the vacuum suspended system, the brakes are applied when
(a) Atmospheric pressure is applied to one side of the diaphragm
(b) Vacuum is applied to both sides of diaphragm
(c) Atmospheric pressure is applied to both sides of the diaphragm

31. In the atmospheric suspended system the brakes are applied when
(a) Vacuum is applied to both sides of the diaphragm
(b) Atmospheric pressure is applied to both sides of the diaphragm
(c) Atmospheric pressure is applied to one side of the diaphragm

32. In a vacuum suspended unit, when the brakes are on, the piston or diaphragm has on both sides of it
(a) Atmospheric pressure
(b) Vacuum
(c) Hydraulic pressure

33. The function of the relay valve in a compressed air brake system is to
(a) Limit the maximum pressure reached in brake chambers
(b) Relieve air pressure in brake chambers when it reaches a maximum value
(c) Reduce the effort required at the brake pedal
(d) Speed up the supply of air to brake chambers located at a distance from brake valve

34. In the hydraulic braking system, the piston in the master cylinder is connected by mechanical linkage to the
(a) Wheel cylinders
(b) Brake shoes
(c) Brake pedal
(d) Wheel pedal

35. In the hydraulic braking system, the movement of the pistons in the wheel cylinder is transmitted to the
brake shoes by
(a) Actuating pins
(b) Springs
(c) Cables
(d) Trunnion
(e) Joints

36. Two general types of vacuum assisted power brakes are (a) Vacuum suspended and power suspended
(b) Integral and pressure suspended
(c) Atmospheric suspended and vacuum suspended
Ans: c

37. In the integral type of power brake, the diaphragm acts directly on the hydraulic piston in the
(a) Master cylinder
(b) Wheel cylinder
(c) Multiplier unit

38. In the multiplier type of brake, the diaphragm acts directly on the hydraulic piston in the
(a) Master cylinder
(b) Wheel cylinder
(c) Multiplier unit

39. In the power assisted type of brake the bellows applies force to the master cylinder piston
(b) Directly

40. In the air brake, air pressure is supplied by
(a) Engine manifold
(b) A compressor
(c) The diaphragm valve

41. Power brakes in general operate making use of the pressure differential between the vacuum from the
intake manifold and
(a) Compressed air
(b) Atmospheric pressure
(c) Venturi vacuum

42. In the multiplier power brake system, movement of the brake pedal
(a) Increases the hydraulic pressure which actuates the control valve
(b) Actuates the valve in the bellows through linkage
(c) Actuates the valve to admit atmospheric pressure to one side of the diaphragm

43. In the power assisted brake system, movement of the brake pedal
(a) Increases the hydraulic pressure which actuates the control valve
(b) Actuates the valve in the bellows through linkage
(c) Actuates the valve to admit atmospheric pressure to one side of the diaphragm

44. The metal used for the brake drum is
(a) Aluminium alloy
(b) Cast steel
(c) Pressed steel
(d) Cast iron

45. Bleeding of brakes means
(a) Filling the master cylinder with brake oil
(c) Removing air between master cylinder and each wheel unit
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46. In trucks the system of wheel braking employed is
(a) Mechanical
(b) Hydraulic
(c) Pneumatic

47. In jeeps we use
(a) Mechanical brakes
(b) Hydraulic brakes
(c) Air brakes

48. In a vacuum type servo-assisted brake system, vacuum is available in …….. is made use of
(a) Exhaust manifold
(b) Combustion chamber
(c) Water jackets
(d) Inlet manifold

49. The approximate ratio of effort applied : effort available from servo system is (a) 1:1
(b) 3:1
(c) 1:4
(d) 10:1

50. Due to continuous running on a hot day the temperature of the braking fluid will increase, hence some
braking torque is applied on brake shoes, to avoid this a small quantity of fluid will be allowed to escape
into the master cylinder through
(a) Intake port
(b) Exhaust port
(c) Secondary port

#### Module 03

1-Leaf springs absorb shocks by
(a) bending
(n) twisting
(c) compression
(d) tension

2-Coil springs absorb shocks by
(a) bending
(b) twisting
(c) compression
(d) tension

3-The following is a type of leaf springs
(a) three Quarter elliptic
(b) semi elliptic
(c) quarter elliptic
(d) all of the above

4-The material used for making torsion bar is
(a) Steel
(b) Cast iron
(c) High carbon steel
(d) All of the above

5-Shackles are sort of
(a) coupling
(c) spring
(d) none of the above

6-Spring shackles are used to join
(a) chassis frame and spring
(b) Spring and Axle
(c) chassis frame and axle
(d) all of the above

7-Drive (live) axles
(a) are simply beams which supports the vehicle weight
(b) are usually the front axles
(c) contain differential
(d) all of the above

(a) are simply beams which supports the vehicle weight
(b) are usually the rear axles
(c) contain differential
(d) all of the above

9-The following represents the correct specification of a tyre
(a) 155-80-R-13
(b) R-155-80-13
(c) 155-80-13-R
(d) 155-R-80-13

10-Telescopic shock observer consists of
(a) One chamber
(b) two chambers
(c) three chamber
(d) four chambers

11-Cam actuated double acting hydraulic shock absorber contains
(a) no piston
(b) single piston
(c) double pistons
(d) three pistons

12-The stabilizers (sway bars) are
(a) alloy steel bars
(b) used to connect shock absorber operating arms
(c) placed parallel to cross members
(d) all of the above

13-The following is (are) the independent suspension system(s)
(a) Wishbone Arm system
(c) Sliding Pillar system
(d) all of the above

14-The coil spring in used in
(a) Wishbone Arm system
(c) Sliding Pillar system
(d) all of the above

15-Un-sprung weight is
(a) Weigh of vehicle
(b) Weigh of chassis frame
(c) Weight of wheels
(d) Weight of wheels and axles

16-Sprung weight is
(a) Weigh of vehicle minus unsprung weight
(b) Weigh of chassis frame
(c) Weight of wheels
(d) Weight of wheels and axles

17-While in motion, the vehicle suspension is subjected to
(a) bouncing
(b) pitching
(c) rolling
(d) all of the above

18-A combination of roll and pitch is called
(a) circular pitch
(b) lateral pitch
(c) transverse pitch
(d) diagonal pitch

19. Which types of wheels cannot be used with a tubeless tire?
a) Disc wheel
b) Light alloy wheel
c) Wire wheel
d) Composite wheel
Explanation: Wire wheels cannot be used with a tubeless tire. Wire wheels are expensive due to their construction. The rim of a wired wheel has holes, due to which it is not possible to fit tubeless tires on wire wheels.

20. Which type of wheels is preferred in sports cars?
a) Disc wheel
b) Wire wheel
c) Magnesium alloy wheel
d) Aluminum alloy wheel
Explanation: Magnesium alloy wheels are preferred in sports cars. Magnesium alloy wheels have high impact and fatigue strength so that they can stand vibration and shock loading better.

21. In case of a wire wheel, the vehicle weight is supported by the wire in _________
a) Tension
b) Bending
c) Shear
d) Compression
Explanation: The vehicle weight is supported by the wire in tension in case of a wire wheel. The side forces on cornering are taken up by the spoke forming triangular arrangement.

22. What does the ‘ply rating’ refer to?
a) Aspect ratio
b) Rated strength
c) Recommended inflation pressure
d) The actual number of plies
Explanation: The ‘ply rating’ refers to rated strength. It is referred to the number of layers of cotton from which the ply is made. The ply rating is high that means the size of the tire is tough.

23. Where will an underinflated tire wear the thread most?
a) Near center
b) Near the edge
c) In the cross direction
d) In the lateral direction
Explanation: An underinflated tire will wear the thread near the edge most. It is sometimes visible in the shape of sidewall cracking.

24. Where will an overinflated tire wear the thread most?
a) Near center
b) Near the edge
c) In the cross direction
d) In the lateral direction
Explanation: An overinflated tire will wear the thread near the center. This type of tire break is caused when an object is hit with a force.

25. What do the permissible of mixing cross-ply and radial-ply automobile tires allow?
a) Cross-ply tires on left wheels
b) Cross-ply tires on right wheels
c) Cross-ply tires on front wheels
d) Cross-ply tires on rear wheels
Explanation: The permissible of mixing cross-ply and radial-ply automobile tires allow cross-ply tires on front wheels. In cross-ply type tires, the ply cords are woven at an angle to the tire axis.

26. What is the purpose of tire rotation on automobiles?
a) Avoid ply separation
b) Equalize wear
c) Get better ride
d) Reduce bump
Explanation: Equalize wear is the purpose of tire rotation on automobiles. The advantage of tires wearing uniformly is wear reduces a tire’s tread depth equally if all the tires wear at the same rate.

27. A car is fitted with 6 * 14 wheels and 185/65 R 14 tires on them. What is the rolling radius of the original tire?
a) 398.05 mm
b) 298.05 mm
c) 288.05 mm
d) 278.05 mm
Explanation: Radius of the wheel = ½ * 14 = 7 in = 177.8 mm. Section height of tire = 0.65 * 185 = 120.25 mm. Rolling radius of the original tires = 177.8 + 120.25 = 298.05 mm.

28. What does the code 145 SR -13 tire designation represent?
a) 145” width, 13” diameter, cross-ply
b) 145 mm width, 13” diameter, radial-ply
c) 145” width, 13 cm diameter, radial-ply
d) 145 mm width, 13 cm diameter, cross-ply
Explanation: The tire designation is of the form width (mm), speed rating, type of ply, and diameter (in) in the same order. So 145 SR – 13 signifies that width = W = 145 mm, speed rating = S which is up to 170 Kmph, the ply is of radial type, and diameter = 13” or 13 in = 330 mm.

#### Module 04

1. What is the colour of a positive plate of a lead-acid battery?
a) White
b) Grey
c) White
d) Brown
Explanation: A positive plate of a lead-acid battery is brown in colour. A negative plate of a lead-acid battery is grey in colour. For each plate, there is a supporting grid made of an alloy of lead and antimony.

2. What gets deposited on the plates of a discharged lead-acid battery?
a) PbO2
b) Pb2O4
c) Pb
d) PbSO4
Explanation: PbSO4 gets deposited on the plates of a discharged lead-acid battery. During discharging the reaction happens in the right direction. PbSO4 gets deposited on both negative and positive plates.

3. What is the twenty-minute rating of battery?
a) Rate of current for 20 minutes with a minimum cell voltage of 1.5 V
b) Time for which the battery can supply 25 A at 80℉ with minimum cell voltage 1.75 V
c) The current which the battery can supply continuously for 30 seconds with minimum cell voltage 1.2 V
d) Lasting power of a battery on a small load
Explanation: The rate of current 20 minutes with a minimum cell voltage of 1.5 V is called a twenty-minute rating of the battery. The temperature of the battery at the start of the test is brought to 80℉. It represents the rate of current a battery can deliver continuously.

4. What is the reserve capacity of battery?
a) Time for which the battery can supply 25 A at 80℉ with minimum cell voltage 1.75 V
b) The current which the battery can supply continuously for 30 seconds with minimum cell voltage 1.2 V
c) Lasting power of a battery on a small load
d) Rate of current for 20 minutes with a minimum cell voltage of 1.5 V
Explanation: The reserve capacity is the time for which the battery can supply 25 A at 80℉ with minimum cell voltage 1.75 V. It is the measurement for the total capacity of the battery.

5. What is the cold rate of a battery?
a) Lasting power of a battery on a small load
b) Rate of current for 20 minutes with a minimum cell voltage of 1.5 V
c) The current which the battery can supply continuously for 30 seconds with minimum cell voltage 1.2 V
d) Time for which the battery can supply 25 A at 80℉ with minimum cell voltage 1.75 V
Explanation: It is a measure of the worst conditions under which a battery is expected to deliver current, e.g., during starting the engine and operating under extreme cold. The cold rate of a battery is the current which the battery can supply continuously for 30 seconds with minimum cell voltage 1.2 V.

6. What is a twenty-hour rate of a battery?
a) The current which the battery can supply continuously for 30 seconds with minimum cell voltage 1.2 V
b) Lasting power of a battery on a small load
c) Time for which the battery can supply 25 A at 80℉ with minimum cell voltage 1.75 V
d) Rate of current for 20 minutes with a minimum cell voltage of 1.5 V
Explanation: A twenty-hour rate of a battery is the lasting power of a battery on a small load. During this test, the temperature should be about 80oF. This rating is important for powering accessories when the engine is not running.

7. What should a fully-charged 6 cell automotive battery indicate?
a) 12 V
b) 12.6 V
c) The specific gravity of 1.29 at 32℃
d) 12.6 V and the specific gravity of 1.29 at 32℃
Explanation: A fully-charged 6 cell automotive battery indicates 12.6 V and a specific gravity of 1.29 at 32℃. There should be no leak. The battery can be checked using a digital multimeter.

8. What is the number of positive plates in a battery cell?
a) One more than the negative plates
b) Two less than the negative plates
c) One less than the negative plates
d) Two more than the negative plates
Explanation: The number of positive plates in a battery cell is one less than the negative plates. One positive and one negative group of plates are sliding over each other, with separators sandwiched between them.

9. What is a maintenance-free battery?
a) A battery having lead-antimony plate grid
b) A battery having lead-calcium plate grid
c) A battery does not contain acid
d) A battery does not contain water
Explanation: A maintenance-free battery is a battery having a lead-calcium plate grid. The battery which uses this plate grid loses water very slowly.

10. Which of the following is the advantage of alkaline battery?
a) High energy density
b) Good discharge characteristics over a wide range of temperature
c) The specific gravity of electrolyte remains the same
d) Cheap raw materials are used
Explanation: The advantage of the alkaline battery is that the specific gravity of electrolyte remains the same. The electrolyte does not take part in chemical reactions on charging or discharging.

11. Which component in the DC generator produces a magnetic field?
a) Stator
b) Commutator
c) Armature
d) Carbon brushes
Explanation: Carbon brushes produce the magnetic field in DC generator. The DC generator is a device which converts mechanical energy into electrical energy. It works on the principle of induced EMF.

12. Which component in alternator produces a magnetic field?
a) Frame
b) Stator
c) Regulator
d) Rotor
Explanation: Rotor in an alternator produces a magnetic field. An alternator is a device that converts mechanical energy to electrical energy and produces the AC current. The rotor is the moving part of the alternator.

13. Why is a thermistor used in an alternator regulator?
a) To control maximum current
b) To control maximum voltage
c) To compensate for temperature change
d) To control minimum current
Explanation: A thermistor is used in an alternator regulator to compensate for temperature change. It is a temperature-sensing device. It alters its physical resistance to change temperature.

14. What is the frequency of a vibrating contact type regulator for DC generator?
a) 20 per second
b) 200 per second
c) 200 per minute
d) 20 per minute
Explanation: The frequency of a vibrating contact type regulator for DC generator is 200 per second. The main parts of the DC generator are frame, armature, and field coils. The parts of the armature are shaft, core, commutator and coil windings.

15. At the start of the engine, the charging voltage is _______
a) Lower
b) Higher
c) Same
d) Zero
Explanation: The charging voltage is high at the start of the engine. The charging voltage should be less than the alternator voltage to charge the battery. The standard battery automotive battery should indicate 12.6 V at 35℃. When the engine is running, it should show 13.7 V to 14.7 V.

16. In an alternator, which component controls the output?
a) Voltage regulator
b) Cutout relay
c) Current regulator
d) Diode
Explanation: Voltage regulator controls the output of the alternator. A voltage regulator is designed so that it keeps a constant voltage level. The voltage regulator is used when the steady and reliable voltage is needed.

17. What is the material of an alternator frame?
a) Cast iron
b) Brass
c) Copper
d) Aluminum
Explanation: An alternator frame is made of aluminum. Aluminum is lightweight. It is no-magnetic. It has a higher thermal conductivity so as to keep the alternator assembly cool by more efficient transfer of heat.

18. If the lead-acid cell has a total of 17 cells, then what is the number of positive plates?
a) 9
b) 8
c) 7
d) 6
Explanation: The number of positive plates in the lead-acid cell is always one less than the number of negative plates. The number of negative plates = 9 and total plates are = 17, therefore, a number of positive plates = 8.

19. Which of the following is not an advantage of the alternator?
a) Higher output
b) Lower weight
c) Less maintenance
d) High efficiency
Explanation: With a lightweight of the alternator, the efficiency of alternator increases. As the output current does not flow through the commutator and brushes, thus surface contamination is eliminated.

20. Field coils in a generator produce permanent magnet.
a) True
b) False
Explanation: Field coils in a generator produce a temporary magnet. The field magnets are electromagnets. These magnets are energized by generator current. The fields magnets have a small residual magnetism this helps in providing the initial field to start the generator operation.

21. Which instrument is used for adjusting the ignition timing?
a) Accurate clock
b) Tachometer
c) Stopwatch
d) Stroboscopic light
Explanation: Stroboscope is used for adjusting the ignition timing. It is the light-emitting device which is connected to the spark plug of the cylinder for setting the ignition timing.

22. Which of the following firing order is commonly used for the four-cylinder vertical engine?
a) 1-2-3-4
b) 3-4-1-2
c) 4-3-2-1
d) 1-3-4-2
Explanation: 1-3-4-2 firing order is commonly used for a four-cylinder engine. For the four-cylinder engine, the firing order is decided such that a power stroke occurs every 180 degrees.

23. What is the dwell time?
a) It is the time for which the contact breaker points remain closed
b) It is the time for which the contact breaker points remain open
c) The time during which inlet and exhaust valves open
d) The time during which inlet and exhaust valves close
Explanation: The dwell time is the time for which the contact breaker points remain closed. Dwell is the time for which the coil turned on.

24. Which of the following is not considered while deciding the optimum firing order of the engine?
a) Engine vibration
b) Engine cooling
c) Development of the backpressure
d) Engine configuration
Explanation: Engine vibration, engine cooling, and development of back pressure are considered while deciding the optimum firing order of the engine. The reduced vibration is required for optimum firing order of the engine.

25. Why is the Dwell meter used?
a) To set the spark plug gap
b) To set the ignition advance
c) To set the contact breaker gap
d) To set ignition timing
Explanation: The dwell meter used for setting the contact breaker gap. It uses the dwell angle as the parameter to set the contact breaker gap. To set the ignition timing stroboscope is used.

26. Which of the following is the disadvantage of the magneto ignition system?
a) Magneto ignition system has a poor quality of spark during starting
b) Magneto ignition system occupies more space
c) Magneto ignition system has more maintenance problems
d) Magneto ignition system is used largely in four wheels
Explanation: During starting, the quality of the spark is poor due to low speed. Magneto ignition system is mainly used in racing cars and two-wheelers. The main advantage is that it does not require a battery.

27. For how many times the contact breaker must make and break the circuit for a four-cylinder engine operating at N rpm?
a) N times
b) 1.5N times
c) N/2 times
d) 2N times
Explanation: The cam is having the same number of lobes as there are engine cylinders. They are used with two contact breakers in parallel.

28. Which of the following is the wrong statement?
a) In the exhaust, retarded timing causes burning of the hydrocarbons
b) The retarded timing improves fuel economy
c) The retarded timing requires the small opening for correct burning of the fuel
d) The exhaust gas temperature becomes higher due to retarded time
Explanation: The retarded timing reduces fuel economy. Due to spark retardation, the fuel burns slowly and after some time than it should be burned.

29. On which condition does the vacuum advance mechanism shift the ignition point?
d) Under sudden acceleration

30. The optimum spark timing must be retarded for the engine operating with a rich mixture.
a) True
b) False
Explanation: The optimum spark timing must be advanced for the engine operating with a rich mixture. The larger throttle opening size means better mixing and combustion.

#### Module 05

1.Two of the three connecting rod bearing loads that increase as engine speeds increase are

2.The central part of the axle beam is offset downwards to
A. Give improved resistance to end thrusts during cornering
B. Give better bending strength
C. Give improved torsional strength during brake application
D. Clear the engine sump and lower vehicle centre of gravity
Answer: Clear the engine sump and lower vehicle centre of gravity

3.X – member of a car frame ensures improved
A. Resistance to side force due to transverse wind load
B. Resistance of weaving and torsional strength of front end of frame
C. Bending strength of side members
D. Resistance to vertical shock loads acting simultaneously on both front wheels

4.The engine is usually supported by the frame
A. Four or five
B. One or two
C. Three or four
D. One or two

5.Parts of the shock absorber include
A. Valves
B. Pistons
C. Coupler
D. Valve springs

6.The unsprung mass in a vehicle system is mainly composed of
A. The frame assembly
B. Gear box and propeller shaft
C. Axle and the parts attached to it
D. Engine and associated parts
Answer: Axle and the parts attached to it

7.The crankshafts are usually forged to get
A. Minimum friction effects
B. A good mechanical design
C. Good grain structure
D. Improved corrosion structure

8.The substance added to the oil which helps to keep the engine clean is called
A.Detergent
B. Soap
C. Thickening agent
D. Grease

9.The pipes used in diesel engines from pump to nozzle is made up of
A. PVC
B. Rubber
C. Steel
D. Copper

10.As the battery is discharged, the active materials in both negative and positive plates are changed to

C. Sulphuric acid

11.The automobile chassis consists of the engine, frame, power train, wheels, steering and …………..
A. Braking system
B. Wind shield
C. The doors
D. Luggage boot

12.The rear end suspension arrangement in which rear end torque is absorbed by the spring is called the
A. Torque tube drive
B. Hotchkiss drive
C. Hooks drive
D. Differential drive

13.On rebound, in the direct acting shock absorber, fluid flows out of the upper part of the cylinder and also ………..
A. Out of the reservoir
B. Into the dust shield
C. Out of the dust shield
D. Into the reservoir

14.The weight or pressure required to deflect a spring in mm is called the spring
A. Rate
B. Rebound
C. Weight
D. Deflection

15.Leaf spring for vehicles are nipped to
B. Improve the load carrying capacity of spring
C. To increase the interleaf friction
D. To vary the effective length of the spring

16.The device that permits variation in the distance between the spring eyes of a leaf spring as the spring flexes is called
A. Spring shackle
B. Spring leaf
C. Spring U – bolt
D. Spring hanger

17.When the direct acting shock absorber is compressed or telescoped fluid passes through the piston orifices into the upper part of the cylinder and also
A. Into the reservoir
B. Out of the reservoir
C. Out of the dust shield
D. Into the dust shield

18.The clips placed at intervals along some leaf spring to prevent spring leaf separation on rebound, are called
A. Rebound clips
B. Relief clips
C. Separation clips
D. Interval clips

19.In a vehicle with torque tube drive, the rear suspension spring
A. Takes up driving thrust and torque reaction
B. Takes up braking thrust and torque reaction
D. Takes up end thrust and torque reaction