Goa Board Class 12 Question Paper Mar 2018 Auto Electicals _New Pattern_

*V372* 2018 III 17 1000 Seat No. : Time : 2 Hours AUTO ELECTRICALS (New Pattern) Subject Code ! % 8 Total No. of Questions : 5 (Printed Pages : 2) Maximum Marks : 50 INSTRUCTIONS : 1) Answer each question on a fresh page. 2) Write questions and sub-questions number clearly. 3) Figures to the right indicate full marks. 4) All questions are compulsory. 5) Illustrate your answer with neat labelled diagrams wherever necessary. 1. A) Answer the following questions in one sentence each : 1) What is the use of high rate discharge cell tester in lead acid battery ? [1] 2) How will you detect short circuit in battery plates ? [1] 3) Why diodes are used in alternator ? [1] 4) What is the function of regulator in generator ? [1] 5) Which instrument is used to check the timing of engine ? [1] 6) What is the purpose of ballast resistance in ignition system ? [1] B) With neat labelled diagram, explain the procedure of specific gravity test conducted in a lead acid battery. [4] 2. A) Answer the following questions : 1) Write the construction of brush assembly in generator. [2] 2) How will you conduct the visual inspection of two wheeler magneto ? [2] 3) Write any four advantages of alternator over dynamo. [2] B) How will you carry out the “stall torque test” on cranking motor ? Explain with the help of line diagram. [4] V-372 -1- P.T.O.

*V372* 3. A) Answer the following questions : 1) How regulator rectifier unit works in two wheeler charging system ? [2] 2) Explain the working of follow thru drive in self starter. [2] 3) Write the functioning of can type ignition coil. [2] B) Draw the neat labelled diagram of spark plug and state any 4 precautions during replacement of spark plug. [4] 4. A) Suggest any four causes and their remedies for the following troubles : 1) Magneto not charging the battery. [2] 2) Normal cranking of engine but it does not start because of faulty ignition system. [2] 3) Starter motor pinion do not dis-engages. [2] B) Draw the neat labelled diagram of improved sealed beam head lamp unit. Also state its four advantages. [4] 5. A) Answer the following questions : 1) How do the central locking function in the car ? [2] 2) How does the windshield washer unit works ? [2] 3) How will you carry out continuity test on rotor of the alternator by using glow lamp ? [2] B) Draw the neat labelled wiring diagram of a balancing coil type temperature guage and explain its construction. [4] –––––––––––––––– V-372 -2-