The candidates were expected to connect the circuit as shown, measure and record the current (mA) and voltage (V) in Table 2 and comment briefly on both readings and the input and output voltages.
The expected answers were:
Resistance RB (Ω) |
0.5 kΩ |
1 kΩ |
2 kΩ |
4 kΩ |
6 kΩ |
8 kΩ |
10 kΩ |
Current (mA) |
2.242 |
2.184 |
2.067 |
1.833 |
1.599 |
1.366 |
1.188 |
Voltage (V) |
10.540 |
9.960 |
8.794 |
6.458 |
4.119 |
1.780 |
0.000 |
(c)
(h) (i) Voltage decreased uniformly with decrease in current.
(ii) Input voltage remained constant at 12 V (DC) and output voltage decreased uniformly from 10.54 V to 0 V.
As reported by the Chief Examiner, the readings obtained by many of the candidates that answered this question showed that they did not know how to adjust meter settings to correspond to indicated values of measured quantities