Question 1
AIM: To determine the characteristics of a simple cell.
- Connect the circuit as shown in Fig. 1.
- Ask the supervisor to check the circuit connection.
- Insert lamps L1, L2, L3 and L4 into the circuit.
- Close switch Sand record the state of the lamps in the spaces provided.
- Measure and record in Table 1 the voltage drop across lamps L1, L2, L3 and L4.
- Comment on the result in step (e).
- Measure and record in Table 1 the current flowing through lamps L1, L2, L3 and L4.
- Comment on the result in step (g).
- Open switch S.
- State two applications of this type of circuit in a motor vehicle.
- State two precautions taken in carrying out the experiment.
Table 1
Lamp |
Voltage drop (V) |
Current (A) |
L1 |
|
|
L2 |
|
|
L3 |
|
|
L4 |
|
|
Observation
The expected answers were
- Correct circuit connection
(d) Lamps L1,L2,L3 and L4 are ON/glow light
(e) In Table 1
(f) The voltages dropped across the lamps are equal
(g) In Table 1
(h) The current is equally divided through the lamps.
Table 1
Lamp |
Voltage drop (V) |
Current (A) |
L1 |
10 – 12 |
1.67 – 2.00 |
L2 |
10 – 12 |
1.67 – 2.00 |
L3 |
10 – 12 |
1.67 – 2.00 |
L4 |
10 – 12 |
1.67 – 2.00 |
(j) Applications of circuit in motor vehicle
- Head light
- Tail light
- Indicator light
- Brake light
(k) Precautions in carrying out the experiment
- I ensured tight connections
- I avoided error due to parallax in meter readings
- I avoided short circuit
Majority of the candidates that attempted this question responded well. Only a few students did not show they understood what was required of them.