Auto Electrical Works Paper 2, WASSCE (SC), 2023

Question 5

 

(a) The headlight is one of the obligatory lights in a motor vehicle.
(i) List two:
I. parts of the headlamp;
II. other obligatory lights in a motor vehicle.
(ii) State two:
I. ways of maintaining a headlamp;
II. symptoms of fault in headlights.
(b)  A simple lighting circuit contains two 100 W lamps, a switch and a 12 V, 60Ahlead-acid battery.
(i) Draw a labelled diagram of the circuit showing the two lamps in parallel, controlled by the switch and connected to the battery
(ii) If each of the lamps draw a current 0.5 A, calculate the time it will take the battery to be completely drained.

Observation

 

The expected responses were:

The expected responses were:

  • (i) I          Parts of the headlamp
  • Bulb
  • bulb holder
  • reflector
  • headlight lens
  • projector lens
  • bulb terminal/ pin
  • filament        
  • high beam
  • low beam

             
II     Other obligatory lights in a motor vehicle

  • reverse light
  • direction indicator
  • parking light
  • brake light
  • hazard light
  • number plate light

(ii) I         Ways of maintaining a headlamp

  • ensure the bulb retaining pin in position
  • ensure that bulb dust boot is in position
  • ensure that the casing is clean
  • ensure the headlamp securing bolts are tightly fixed
  • frequently check the alignment of the headlight

                  II   Symptoms of fault in headlights

  • flickering light
  • dim light
  • no illumination/poor illumination
  • poor aiming/focusing

 

  • (i) Diagram of  a simple lighting circuit showing two 100W lamps in parallel, a switch and a 12V, 60Ah lead-acid battery

  (ii)  Calculation
                  Current = 0.5 + 0.5 = 1.0 A
                   Time =
                              = 60 hours

Candidates performed relatively well in this question. The weak areas include the maintenance of headlights, faults in headlight and calculation on discharge time of battery.