ALTERNATING CURRENT AND DIRECT CURRENT

4 marks · Normal

A 12 V battery is connected to a lamp. The current in the lamp is measured as 0.4 A.

(a)

Calculate the power supplied to the lamp.

[2 marks]

(b)

Calculate the energy transferred by the lamp in 2 minutes.

[2 marks]

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Show answer

(a) 4.8 W

(b) 576 J

Common mistakes: Not converting minutes to seconds

Show mark scheme and worked solution

Marking points

M1 (a) · 1 mark · Applies correctly. (follow-through)

A1 (a) · 1 mark · Correct calculation of power: 4.8 W. (follow-through)

M2 (b) · 1 mark · Uses with time in seconds (2 min = 120 s). (follow-through)

A2 (b) · 1 mark · Correct calculation of energy: 576 J. (follow-through)

Worked solution

b) 2 minutes = 120 seconds