AIM: To investigate the variable base resistor in Zener-transistor regulating circuit.
(a)Connect the circuit as shown in Figure 1.
(b) Ask the Supervisor to check the circuit connection.
(c)Copy Table 1 into your answer booklet.
Table 1
Resistance RB (Ω) |
1 kΩ |
2 kΩ |
4 kΩ |
6 kΩ |
8 kΩ |
10 kΩ |
Current (mA) |
|
|
|
|
|
|
Voltage (V) |
|
|
|
|
|
|
(d)Use the multimeter to measure the resistance of the potentiometer at 1 kΩ.5
(e)Switch on the power supply, measure and record the corresponding values of current (mA) and voltage (V) in Table 1.
(f) Switch off the power supply.
(g) Repeat step (e) for the other values of RB in Table 1.
(h) Using the results in Table 1, plot a graph of voltage (V) on the vertical axis against current (mA) on the horizontal axis.
