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.