An electric lamp is rated 240V, 40W. What is the cost of running the lamp...

PHYSICS
WAEC 2005

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

Correct Answer: A. N7.20

Explanation

Cost = \(\frac{Pt}{1000}\) x cost per kWh

= \(\frac{40 \times 72}{1000} \times 2.50 = N7.20\)



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