Class 12 Automotive Chapter 3 Transmission System

Class 12 Automotive Chapter 3 Transmission System Solutions English Medium As Per AHSEC New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters Class 12 Automotive Chapter 3 Transmission System Question Answer and select need one. Class 12 Automotive Chapter 3 Transmission System Notes Download PDF. AHSEC Class 12 Elective Automotive Question Answer English Medium.

Class 12 Automotive Chapter 3 Transmission System

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Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. AHSEC Class 12 Elective Automotive Textual Solutions are part of All Subject Solutions. Here we have given AHSEC Class 12 Automotive Textbook Solutions English Medium for All Chapters, You can practice these here.

Transmission System

Chapter: 3

A. Fill in the blanks:

1. Diaphragm clutch is advantageous over spring clutch as it transmits more torque due to the use of a diaphragm ______________. 

Ans: Spring.

2. During the process of overhauling a clutch assembly, it is important to inspect the clutch plate for ____________ and check its thickness. 

Ans: Oil Leakage.

3. Clutch slip occurs when power transmission is not properly ____________ to the gearbox even after releasing the clutch plate. 

Ans: Transmitted.

4. A weakened diaphragm spring can be one of the causes of_____________.

Ans: Clutch Judder.

B. Multiple Choice Question Question: 

1. What type of clutch uses a diaphragm spring instead of a coil spring? 

(a) Spring clutch. 

(b) Multi-plate clutch. 

(c) Centrifugal clutch. 

(d) Diaphragm clutch.

Ans: (d) Diaphragm clutch.

2. Why is a diaphragm clutch advantageous over a spring clutch? 

(a) It has larger size. 

(b) It requires more maintenance.

(c) It transmits more torque. 

(d) It is less affected by centrifugal force Question.

Ans: (c) It transmits more torque.

3. What is the primary purpose of overhauling a clutch assembly? 

(a) To increase rotational speed. 

(b) To replace the engine.

(c) To improve fuel efficiency.

(d) To restore proper functioning and efficiency.

Ans: (d) To restore proper functioning and efficiency.

4. Clutch slip occurs when: 

(a) The clutch pedal is released slowly. 

(b) Power transmission is not transmitted to the gearbox after releasing the clutch plate. 

(c) The engine stalls. 

(d) The clutch pedal is pushed all the way to the floor.

Ans: (b) Power transmission is not transmitted to the gearbox after releasing the clutch plate.

C. Answer the following questions:

1. What is the importance of reconditioning and overhauling the clutch of a vehicle?

Ans: When the clutch runs with noise and clutch slips and it does not engage and disengage properly, it may result in jerky movement in engagement and as well as disengagement. Then it is necessary to overhaul the clutch assembly.

2. What are the functions of clutch in vehicle? 

Ans: Clutch is used to connect and disconnect the engine power to the gear box as per requirement. 

3. When is the clutch plate changed in a vehicle?

Ans: Clutch plate is changed when it is worn out, thickness is reduced or oil is leaked on the clutch plate.

4. Enlist the components of clutch system?

Ans: Pressure plate, Clutch disc, Release bearing, Flywheel.

5. What components are linked to the gear input shaft?

Ans: Clutch plate and Gear box input shaft are linked together.

6. Why the clutch springs are used in clutch plate?

Ans: Clutch springs are used to absorb torsional vibration produced in the transmission system.

A. Fill in the blanks:

1. If the dial gauge shows a deflection of 2 mm, it indicates that the propeller shaft is _______________. 

Ans: Bent.

2. The drive shaft is responsible for transmitting power from the _______________ to the ______________. 

Ans: Engine, wheels.

3. To prevent squeaking noise, it’s recommended to lubricate the _______________ joints and propeller shaft. 

Ans: Universal.

4. The drive shaft assembly consists of inboard joint, wheel side joint, and ______________ joint. 

Ans: Steering Knuckle.

B. Multiple Choice Questions: 

1. What is the purpose of a propeller shaft in a vehicle? 

(a) To clean the engine. 

(b) To transmit power between the gearbox and differential.

(c) To steer the vehicle. 

(d)To control suspension. 

Ans: (b) To transmit power between the gearbox and differential.

2. Which component connects the engine to the wheels and is usually made of steel? 

(a) Steering wheel. 

(b) Drive shaft. 

(c) Universal joint. 

(d) Differential gear. 

Ans: (b) Drive shaft.

3. What is the consequence of a bent propeller shaft? 

(a) Improved fuel efficiency. 

(b) Reduced noise. 

(c) No effect on performance. 

(d) Noisy operation. 

Ans: (d) Noisy operation.

4. What should be done if the universal joint cross is worn out? 

(a) Replace the propeller shaft.

(b) Clean the joint with solvent. 

(c) Replace the universal joint cross. 

(d) Lubricate the differential.

Ans: (c) Replace the universal joint cross.

C. Answer the following questions: 

1. What is the purpose of using propeller shaft/driveshaft in the vehicle?  

Ans: When the engine and axles are separated from each other on four-wheel (4W) rear-wheel-drive (RWD) vehicles, the propeller shaft is used to transmit engine power to the rear drive axles. The propeller shaft is mounted between the gearbox and differential and thus the engine power is transmitted to the driving wheels.

2. Explain the various parts of the propeller shaft/driveshaft. 

Ans: The propeller shaft consists of the following parts:

(i) Yoke.

(ii) Cross.

(iii) Bearing cup.

(iv) Dust cover.

(v) Slip joint.

3. When universal joint & slip joint need replacement?

Ans: If the readings are not found in permissible values replace the universal joint and slip joint.

4. Describe the functions of a drive shaft.

Ans: A drive shaft is a solid circular shaped shaft usually made of steel which transmits power from engine to gear and then to the wheels of a vehicle.

A. Fill in the blanks:

1. The differential allows wheels to rotate at ______________ speeds when a vehicle turns. 

Ans: Different.

2. The primary function of the differential is to transfer engine power to the ____________. 

Ans: Wheels.

3. Proper adjustment of backlash ensures correct tooth _______________ between gears. 

Ans: Contact.

4. In the differential, the components responsible for transmitting torque to the wheels are the half axle _______________.

Ans: Shaft.

B. Multiple-Choice Questions: 

1. What is the main purpose of a differential in a vehicle? 

(a) To increase engine power. 

(b) To reduce fuel consumption. 

(c) To allow wheels to rotate at different speeds during turns. 

(d) To control steering alignment. 

Ans: (c) To allow wheels to rotate at different speeds during turns.

2. Which of the following gears is NOT a part of a differential? 

(a) Crown gear.    

(b) Sun gear.

(c) Star gear.

(d) Drive gear. 

Ans: (d) Drive gear.

3. The differential’s job includes: 

(a) Increasing transmission speed. 

(b) Slowing down engine power.

(c) Transferring power to the wheels and allowing speed variation during turns. 

(d) Providing suspension support. 

Ans: (c) Transferring power to the wheels and allowing speed variation during turns.

4. When a vehicle turns, which wheels travel a shorter distance? 

(a) Front wheels. 

(b) Rear wheels. 

(c) Left wheels. 

(d) Outside wheels.

Ans: (a) Front wheels. 

C. Answer the following questions:

1. What is the function of differential unit?

Ans: A differential is a device employing gears, capable of transmitting torque and rotation through three shafts. It transfers the power while turning to the respective wheels.

2. What is the importance and working of differential? 

Ans: A vehicle wheel rotates at different speeds, especially while turning. Each wheel has to travel a different distance while turning. In addition, the inner wheel has to travel a shorter distance than the outer wheel. Since speed is equal to the distance travelled divided by the time it takes to go that distance, the wheels that travel a shorter distance travel at a lower speed. Also note that the front wheels travel a different distance than the rear wheels.

3. What are the main parts of differential? 

Ans: It consists crown gear, sun gear and star gear.

4. Write the steps to adjust crown wheel and pinion clearance.

Ans: (i) If there is heavy face contact then remove the shims from the bevel pinion and move the pinion towards the crown wheel.

(ii) If there is heavy flank contact, then add the shims in the pinion and pull out the pinion away from the crown wheel.

(iii) If there is heavy toe contact then remove the shims from the right hand side and add shims towards the left hand side of the crown wheel.

(iv) If there is heavy heel contact, add the shims towards the right hand side of the crown wheel.

5. What rotates the differential pinion shafts?

Ans: Input torque is applied to the ring gear, which turns the entire carrier, providing torque to both side gears, which in turn may drive the left and right wheels.

6. To which gear half shaft splines are connected?

Ans: Check the internal splines of the sun gear and external spline of the half axle shaft for stripping.

7. What kind of joint is used to link differential with shaft & why?

Ans: Universal joint is used to link differential with shaft because it can transmit power at an angle with variation of position.

8. What lubricants are commonly used in differential?

Ans: Servicing differentials means changing the oil regularly with the proper grade as per the service manual.

A. Fill in the blanks:

1. The gearbox is positioned between the engine and ____________ or differential in a vehicle’s drivetrain to overcome various forms of resistance and enhance engine power. 

Ans: The propeller shaft.

2. In maintenance of the gearbox, it’s important to carry out oil changes at regular intervals to ensure proper ____________. 

Ans: Lubrication.

3. The _______________ of the gear selective mechanism should be inspected periodically, and necessary adjustments should be provided. 

Ans: Components.

4. An automatic transmission system can change gear ratios automatically using a torque converter and a complex _____________ system.  

Ans: Planetary gearing

B. Multiple Choice Questions: 

1. What is the primary purpose of a gearbox in a vehicle’s drivetrain? 

(a) To amplify the engine’s noise. 

(b) To reduce engine power. 

(c) To overcome various resistances and enhance engine power.

(d) To decrease the vehicle’s efficiency. 

Ans: (c) To overcome various resistances and enhance engine power.

2. Which of the following is NOT a resistance that a gearbox helps to overcome? 

(a) Air resistance.

(b) Gradient resistance. 

(c) Load resistance. 

(d) Fuel resistance. 

Ans: (d) Fuel resistance. 

3. Which component is responsible for changing gear ratios automatically in an automatic transmission? 

(a) Clutch plate. 

(b) Torque converter. 

(c) Synchronizer ring.

(d) Differential gear. 

Ans: (b) Torque converter.

4. What does ATF stands for in the context of an automatic transmission system? 

(a) Advanced Transmission Fluid. 

(b) Automatic Torque Factor.

(c) Automatic Transmission Fluid. 

(d) Automated Transmission Feature. 

Ans: (c) Automatic Transmission Fluid.

5. Which part of the automatic transmission system replaces the clutch of manual transmissions? 

(a) Torque converter. 

(b) Gear shifter. 

(c) Synchronizer. 

(d) Planetary gear.

Ans: (a) Torque converter. 

6. What is the function of the planetary gearing system in an automatic transmission? 

(a) To regulate engine power. 

(b) To change tyre pressure. 

(c) To provide different gear ratios.

(d) To control air conditioning.  

Ans: (c) To provide different gear ratios.

B. Answer the following questions:

1. What are main components of automatic transmission? 

Ans: Main components of an automatic transmission are converter housing case, oil pan, and extension housing.

2. How many types of automatic transmission are used in a vehicle?

Ans: There are two types of Automatic transmission namely automated manual transmission (AMT) and continuously variable transmission (CVT).

3. State the working principle of automatic transmission.

Ans: We can say that an automatic transmission is an automobile gearbox that can change gear ratios automatically as the vehicle moves under varying conditions, thus freeing the driver from shifting the gears manually.

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