An electric lamp is rated 240V, 40W. What is the cost of running the lamp for 72 hours if the electricity authority charges N2.50 per kWh?
A
N7.20
B
N18.00
C
180.00
D
N720.00
Verified Correct Answer: A.
Physical Principles & Numerical Solution
Cost = \(\frac{Pt}{1000}\) x cost per kWh
= \(\frac{40 \times 72}{1000} \times 2.50 = N7.20\)
Source: Myschool Past Questions Archive (Record #34532)