ELECTRICAL POWER

3 marks · Easy

A 60 W lamp is switched on for 5 seconds.

(a)

State what the lamp’s power rating of 60 W means.

[1 mark]

(b)

Calculate how much energy is transferred by the lamp in 5 seconds.

[2 marks]

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(a) The lamp transfers 60 joules of energy each second.

(b) 300 J

Show mark scheme and worked solution

Marking points

B1 (a) · 1 mark · States that the lamp transfers 60 joules of energy per second.

M1 (b) · 1 mark · Uses correct formula: energy = power × time.

A1 (b) · 1 mark · Correct answer: 300 J. (follow-through)

Worked solution

a) The lamp's power rating means it transfers 60 J of energy per second.

b) Energy = power × time.