Goa Board Class 12 Question Paper June 2018 Auto Transmission

*V323* 2018 VI 08 1430 Seat No. : Time : 2 Hours AUTO TRANSMISSION Subject Code Total No. of Questions : 5 (Printed Pages : 2) Maximum Marks : 50 Instructions : I) All questions are compulsory. II) Answer each question on a fresh page. III) Write the number of the questions and sub-questions clearly. IV) Figures to the right indicate full marks. 1. A) Answer the following questions in one sentence each : I) Name the material used in the manufacture of the pressure plate of a single plate clutch. [1] II) State the component provided between the star pinion and the cage of a differential unit to avoid wear and tear. [1] III) State any two advantages of using Tubeless Tyres. [1] IV) State any two disadvantages of using coil springs in the suspension system. [1] V) Name the type of stub axle used more popularly in commercial vehicles. [1] VI) Why understeer is safer than over steer ? [1] B) i) Draw a neat labelled sketch of ‘semi-centrifugal clutch’. [2] ii) What are the materials used in the manufacture of clutch facing other than asbestos ? Why asbestos is preferred as a clutch facing ? [2] 2. A) Answer the following questions : i) Why more number of clutch plates are used in multiplate wet type clutch ? [2] ii) What is “Air or wind resistance” ? [2] iii) Explain the working of constant mesh gear box. [2] V-323 -1- P.T.O.

*V323* B) i) Draw a neat labelled sketch of torque tube drive. [2] ii) Explain in short the cross and yoke type universal joint. [2] 3. A) Answer the following questions : i) Why is overdrive provided in an Automobile ? [2] ii) State any four requirements of a road wheel ? [2] iii) Write a short note on “Telescopic shock absorber”. [2] B) i) Draw a neat labelled sketch of semi-floating axle. [2] ii) Explain the constructional features of a differential unit. [2] 4. A) Answer the following questions : i) Mention the characteristics of suspension system (Any four). [2] ii) Explain the constructional details of worm and roller steering gear box. [2] iii) State any four requirements of steering system. [2] B) i) Draw a neat labelled sketch of conventional chassis frame. [2] ii) Give any four points of difference between the chassis and the frame. [2] 5. A) Answer the following questions : i) State the functions of the following components : a) Tie rod. [1] b) Steering gear box. [1] ii) Describe the Tandem master cylinder of Hydraulic brake system. [2] iii) Compare independent suspension system with conventional suspension system. [2] B) i) Draw a layout of Hydraulic Brake System. [2] ii) Why unloader valve is provided in “Air Braking System” ? [2] ­­­­­­­­­­­­­–––––––––––– V-323 -2-