Revision NotesExam QuestionsPast Papers
O LevelPhysicsCambridge (CIE)Exam Questions4. Electricity & Magnetism4.4 Practical Electricity

Practical Electricity (Cambridge (CIE) O Level Physics): Exam Questions

27 mins16 questions

Select a download format for 4.4 Practical Electricity

Scroll for more

Select an answer set to view for
4.4 Practical Electricity

1a
Sme Calculator4 marks

A teacher uses a power supply in a metal case. The circuit for the power supply includes a fuse.

(i) Draw the electrical symbol for a fuse.

[1]

(ii) The metal case of the power supply is earthed. A fault occurs and a live wire touches the metal case.  

Explain how earthing the metal case protects the teacher.

[3]

How did you do?

1b
Sme Calculator3 marks

The power supply circuit includes a transformer. Its input voltage is 240 V. There are 960 turns on the input coil and 64 turns on the output coil.

Calculate the output voltage of the transformer.

output voltage = ..................................................... V 

How did you do?

Did this page help you?

2a
Sme Calculator3 marks

Fig. 8.1 shows a circuit containing a 230 V a.c. supply connected to a television and two lamps. 

q8-cie-ol-physics-specimen-paper-2-sq

Fig. 8.1

In normal operation, both switches are closed. The power supplied to each lamp is 40 W and the power supplied to the television is 120 W.

Calculate, in normal operation:

(i) the total number of kilowatt-hours (kW h) of energy supplied to the circuit in 1.0 hour

  number of kW h = .......................................................... [1]

(ii) the current in each lamp.

current = ....................................................... A [2]

How did you do?

2b
Sme Calculator2 marks

Explain why the switches are placed in the live wire and not in the neutral wire.

How did you do?

2c
Sme Calculator1 mark

State one advantage of connecting the two lamps in parallel in this circuit.

How did you do?

Did this page help you?