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Monday, 17 August 2026
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Physics Past Questions and Answers

Topic: Electrical Energy and Power

Jamb Physics Questions - Electrical Energy and Power

Question 16:
The cost of running five 60 W lamps and four 100 W lamps for 20 hours if electrical energy cost #10.00 per kwh is
  • A 280.00
  • B 160.00
  • C 120.00
  • D 140.00
View Answer & Explanation
Question 17:
An electric iron is rated 1000W, 230V. What is the resistance of its elements?
  • A 51.9Ω
  • B 52.9Ω
  • C 55.9Ω
  • D 57.6Ω
View Answer & Explanation
Question 18:
From the generating station to each substation power is transmitted at a very high voltage so as to reduce
  • A Hysteresis loss
  • B Eddy current loss
  • C Magnetic flux leakage
  • D Heating in the cells
View Answer & Explanation
Question 19:
A step-down transformer has a power output of 50 W and efficiency of 80%. if the mains supply voltage is 200 v, calculate the primary current of the transformer.
  • A 0.31 A
  • B 3.20 A
  • C 3.40 A
  • D 5.00 A
View Answer & Explanation
Question 20:
An electric lamp marked 240v, 60 W is left to operate for an hour. How much energy is generated by the filament?
  • A 3.86 x 10<sup style='font-size: smaller;'>5</sup>J
  • B 3.56 x 10<sup style='font-size: smaller;'>5</sup>J
  • C 1.80 x 10<sup style='font-size: smaller;'>4</sup>J
  • D 2.16 x 10<sup style='font-size: smaller;'>5</sup>J
View Answer & Explanation