A lamp rated 100W, 240V is lit for 5hours. Calculate the cost of lighting the lamp if 1kWh of electrical energy cost N5.
-
A.
N2.50 -
B.
N3.20 -
C.
N6.50 -
D.
N9.60
Correct Answer: Option A
Explanation
Power = 100W; Voltage = 240V; Time = 5 hours
Total energy used = Power x time = 100 x 5 = 500wh
converting to kwh, we have
(frac{500}{1000} = 0.5kWh times N5 = N2.50)