(a)(i) This question posed no problem to majority of the responding candidates.
(ii) Performance was poor.
(b) Candidates' were expected to recognize that more current passes through the 200W bulb
hence higher brightness. Majority ofthe candidates performed satisfactorily.
(c) This was a numerical problem and candidates' reactions were fairly satisfactory.
(d) This was another numerical problem. Quite a few candidates got the required circuit
diagram right. However, the application ofthe formula linking Q, C and V posed no
problem to many candidates. Performance was good.
The expected answers are:
(a)(i)A capacitor is a device for storing charges/electrical energy.
A capacitor is a device consisting of two parallel metal plates, carrying equal but
opposite charges separated by a dielectric/an insulator.
(ii) A short circuit
An electrical connection of relatively very low resistance made between two
points (at different potentials) in a circuit
When two wires touch and the resistor in the circuit is by-passed/there is not
enough resistance in the circuit.
More current passes through the 200 watt bulb than the 60 watt bulb and the more current
that passes through the bulb the brighter and more powerful the bulb.
Ca = 5
1/Cb = 1/C3 + 1/C4 =1/10 + 1/10 + 1/5
Cc = Ca + Cb = 5+ 5 =10
1/Cxy = 1/10 + 1/10 = 2/10
Cxy = 5