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 Electronics Paper 1, May/June 2008
 Questions: 1 2 Main
Weakness/Remedies
Strength

Question 1

1. The aim of both experiments is to investigate the operation of diodes.

1. Connect the circuit as shown in Figure 1 using the silicon diodes D1, D2, D3,D4­
2. Ask the supervisor to check the circuit connection.

Table 1

 V1(V) V2(V) V3(V) V4(V) VL(V) IL =VL/RL Silicon Germanium

(d) Close switch S1
(e) Measure and record in Table 1, the voltage drops V1 to V4 respectively.
(f)  Measure and record in Table 1, the load voltage VL.
(g) Open switch S1 and disconnect the diodes.
(h) Calculate and record in Table 1, IL.
(i) Reconnect the circuit with the germanium diodes Ds, D6, D7, Ds.

(j) Repeat steps (d) to (h) to complete Table 1
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OBSERVATION

This question was to demonstrate the use of multimeter as a voltmeter and an ohmmeter.  It further required candidates to identify colour bands, measure resistance and voltages, compare corresponding results with comments and identify the relevant circuit law.

The poor usage of measuring instrument affected majority of the candidates, with the computations dependent on the wrong values got from the measured quantities.