Applied Electricity Paper 2 , Nov/Dec. 2011

Questions:		1	2	3	4	5	6		Main

General Comments
Weakness/Remedies
Strength

Question 1

Define Impedance.
Draw and label an impedance triangle for a series RC circuit.
A circuit consists of a 12 V battery, a switch, and a lamp. When the switch is closed, a current of 3 A flows in the circuit.
Sketch the circuit diagram.
Calculate the resistance of the lamp.

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Observation

The expected answers were:

Impedance is the total opposition to the flow of an alternating current.

The question was on Alternating Current Circuit Theory. It was quite popular with the candidates.
Many of the candidates who attempted the question got the definition right.
However, the importance of resonance was not well understood due to faulty circuit diagram.

R =
= = 4 Ω

The question was on Direct Current Circuit Theory. It was well attempted by candidates. The candidates’ performance was reported good.