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Right OPTION is (B) False

To ELABORATE: 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.

Right answer is (C) 225.5°

Explanation: (ωB / ωA) = (cos α) / (1 – cos^2θ sin^2α) where A = driving shaft and B = driven shaft and α is the ANGLE between shaftA and shaft B. θ is the angle through which the shaft A rotates. Acceleration will be maximum when cos2θ = (2 sin^2α) / (2 – sin^2α) =(2 sin^240°) / (2 – sin^240°) = 0.5207 i.e. 2θ = 58.62i.e. θ = 29.31°, 180° – 29.31° = 150.69°, 180° + 29.31° = 209.31°, 360° – 29.31° = 330.69°

Correct answer is (d) 141.52°

The EXPLANATION: (ωB / ωA) = (cos α) / (1 – cos^2θ sin^2α) where A = driving shaft and B = driven shaft and α is the angle between shaftA and shaft B. θ is the angle through which the shaft A rotates. VELOCITY ratio is unity when tanθ = ± \(\SQRT{cos\alpha} = ± \sqrt{cos35}\) = ± 0.90 i.e. θ = 42.145°, 222.145°, 317.85°, and 137.85°.

The correct answer is (c) To TRANSFER TORQUE at an angle

For 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.

The CORRECT option is (a) Between transmission and rear axle

The best I can explain: 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.

Correct OPTION is (a) Sun gear stationary, ring gear DRIVEN, planet CARRIER driving

The 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.

The correct option is (d) SLIDING MESH gearbox

Easiest 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.

Correct CHOICE is (b) False

The 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.

Right choice is (a) Springs

To EXPLAIN: 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.

Correct answer is (a) It becomes DIFFICULT to disengage the clutch when the CONE angle is less than 20°

Easy 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.

Correct choice is (c) 0.4

The best I can explain: 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.

Correct answer is (a) Clutch – by – WIRE

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.

Right CHOICE is (C) 6

The 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.

Correct option is (d) Sends most of the power to the WHEEL having less traction

To explain: 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.

Correct answer is (B) 0°, 180°

To explain I would say: (ωB / ωA) = (cos α) / (1 – cos^2θ sin^2α) where A = driving SHAFT and B = driven shaft and α is the angle between shaftA 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°.

The correct answer is (d) There is relative motion between TEETH

Easiest 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.

The CORRECT option is (b) To vary the torque of the vehicle

For explanation I WOULD SAY: 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.

The correct ANSWER is (d) 78

Easy 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.

Right OPTION is (B) False

For 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).

Correct answer is (a) CONSTANT-mesh gearbox

For 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.