Basic Electronics Paper 3, WASSCE (SC), 2021

Question 1

AIM: The aim of both experiments is to investigate the function of Zener diode in a transistor series voltage regulator.

 

  1.   Connect the circuit diagram as shown in Figure 1.
  2.   Ask the Supervisor to check the circuit connection.
  3.   You are provided with Table 1.

 

Table 1

Vin (V)

Vout (V)

2

 

4

 

6

 

8

 

10

 

12

 

 

  1. Set the power supply unit to 2 V.
  2. Close switch (S)
  3. Read and record in Table 1 the value of Vout .
  4. Open switch (S)
  5. Repeat steps (d) to (g) for the other values of Vin in Table 1.
  6. Plot a graph of Vout (V) on the vertical axis against Vin (V) on the horizontal axis

 

Observation


The expected responses were:


Table 1


Vin (V)

Vout (V)

2

1.0 - 2.0

4

3.0 - 4.0

6

5.0 - 6.0

8

7.0 - 8.0

10

9.0- 10.0

12

11.0 - 12.0

 

 

 

 

 

 

 

 

 

 

(i)    A linear graph with origin (0, 0) with features such as title, labelled axes, appropriate scales, correct point picking and line of best fit.