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JAMB Physics 1978 Question 28

Question 28

Electrical Energy and Power

If NEPA charges 5k per kWh, what is the cost of operating for 24 hours a lamp requiring 1 A on a 200 V line?

  1. A.24K
  2. B.55K
  3. C.40K
  4. D.26K
  5. E.32K.
Show the answer and explanation

Answer: A (24K)

Explanation

Power = IV = 200 W = 0.2 kW. Energy = 0.2 × 24 = 4.8 kWh, and 4.8 × 5k = 24k.