Auto Electrical Works Paper 2, WASSCE (SC), 2019

Question 1

 

 

       
        
  1.   Table 1 contains the terminals of a lead-acid battery.
  2.                                                             Table 1


    Features

    Positive terminal

    Negative terminal

    Sign

     

     

    Colour

     

     

    Size

     

     

                State in Table 1 the difference in the features of the terminals.

          

  3. In a motor vehicle battery, state two:

    •      
    •    symtoms of fault.

    •       
    •   functions of the filler cap.

           
  4. Name the equipment used in testing the following properties of a battery.

    •         Specific gravity

    •         Cell voltage

    •       Polarity

 

Observation


The Chief Examiner reported that majority of the candidates that attempted question 1 did not respond well. Only a few were able to differentiate between positive and negative terminals of a lead-acid battery. It was also reported that many others could not state the symptoms of fault in a motor vehicle battery nor name correctly equipment required for testing the specified properties of a battery.

The expected responses were:


  1. Features Positive terminal Negative terminal
    Sign Plus (+) Negative (-)
    Colour Red/brown Blue/green/black
    Size Big/bigger Small/smaller

  2. i
      • Symptoms of fault in a motor vehicle battery

      • Slow cranking of engine

      • Swollen/bloated battery case

      • Battery indicator light staying ON

      • Leakage of battery ele

      • Pre-mature discharge

      • Battery discharge or weak

      • Overcharge

      Functions of filler cap in a motor vehicle battery


    • To prevent electrolyte spillage

    • To provide room for electrolyte re-filling

    • To allow for the escape of hydrogen gas

    • To prevent pressure build up

  3. Equipment used in testing


  4. i Specific gravity:

    Hydrometer
    ii Cell voltage: Multimeter/voltmete
    iii Polarity: Multimeter/ohmmeter