Question 1
- Fig. 1 is the diagram of an instrument used for testing the condition of batteries in Auto
Electrical Works (AEW) workshop.
- State the:
- name of the instrument;
- function of the instrument.
- State, in five steps, how the instrument is used to perform the function mentioned in
1(a) (i)II.
- State the condition of the battery if the instrument reads:
- I.150;
- 1.300.
- State the remedy, if any, required on the battery:
- when the reading is 1.150;
- when the reading is 1.300.
- State three precautions that should be taken in carrying out the remedies stated in 1 (a)(iv).
- Fig. 2 is the circuit diagram of a vehicle headlight sub-system
- State the:
- Type of circuit connection in Fig.2;
- Effect of burnt fuse on lamp
- Table 1 contains the conditions of switches and for the operation of the headlamps in Fig. 2. Study Fig.2 and complete Table1 by indicating the state of lamps , , and as either ON or OFF for each condition of switches.
Table 1
Conditions of switches |
|
|
|
|
open and open |
|
|
|
|
closed and open |
|
|
|
|
open and closed |
|
|
|
|
closed and closed |
|
|
|
|
The expected responses were:
- (i) I. State the name of the instrument
- Hydrometer
II. Function of the instrument
- Measure/test specific gravity of the electrolyte of a battery
- Measure the state of charge of a battery
(ii) How the instrument is used to perform the function mentioned in 1(a)(i)II
- Inject the syringe into a cell of battery
- Squeeze the rubber bulb
- Release the rubber bulb to suck in electrolyte
- Raise/remove the syringe from the cell
- Raise/hold vertically to take readings
(iii) I. The condition of the battery if the instrument reads 1.150
- In charge/completely discharged
II. The condition of the battery if the instrument reads 1.300
- Fully charge
(iv) I. The remedy, if any, required on the battery when the reading is 1.150
- Requires charging
II. The remedy, if any, required on the battery when the reading is 1.300
- Can be used
(v) The precautions that should be taken in carrying out the remedies stated in 1(a)(iv)
- Wear eye protection
- Avoid flames or spark
- Always turn the battery charger off before connecting the lead
- The charging room must be well ventilated
- Disconnect the negative battery cable if the battery is to remain in the vehicle during the charging process
- Use proper adapters to connect charger lead to side terminal batteries
- (i) I. The type of circuit connection in Figure 2
- Parallel connection
II. The effect of burnt fuse on lamp in Figure 2
- will not glow/come on
(ii) Table 1
Conditions of switches |
|
|
|
|
open and open |
OFF |
OFF |
OFF |
OFF |
closed and open |
OFF |
ON |
ON |
OFF |
open and closed |
ON |
OFF |
OFF |
ON |
closed and closed |
ON |
ON |
ON |
ON |
Question 1 required candidates to show familiarity with features and treatment of a lead-acid battery and lighting system. The Chief Examiner reported that majority of the candidates who attempted question 1 were only able to respond to the few recall tasks but largely unable make the appropriate deductions.