A lamp rated 100W, 240V is lit for 5hours. Calculate the cost of lighting the lamp if 1kWh of electrical energy cost N5.

By: |Published on: Jan 24|Categories: Physics WAEC| 0 comments

A. N2.50
B. N3.20
C. N6.50
D. N9.60

Correct Answer: Option A

A. N2.50

Explanation

Power = 100W; Voltage = 240V; Time = 5 hours

Total energy used = Power x time = 100 x 5 = 500wh

converting to kwh, we have

500/1000=0.5kWh×N5=N2.50

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