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Wednesday, 15 April 2026
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Physics Past Questions and Answers

Topic: Explanation of a.c. current and voltage

Jamb Physics Questions - Explanation of a.c. current and voltage

Question 1:
In fig 9 the value of R is
  • A 3Ω
  • B 4Ω
  • C 5Ω
  • D 6Ω
View Answer & Explanation
Question 2:
A 120 V, 60 W lamp is to be operated on 220 V a.c. the supply mains. calculate the values of non-inductive resistance that would be required to ensure that the lamp is run on current value.
  • A 100 Ω
  • B 200 Ω
  • C 300 Ω
  • D 500 Ω
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Question 3:
The r.m.s value of a supply voltage is quoted at 200v. What is the approximate peak value of the voltage?
  • A 200volts
  • B 300volts
  • C 283volts
  • D 250volts
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Question 4:
When the r.m.s value of a source of electricity supply is given as 240v, it means that the peak value of the supply is
  • A 240v
  • B 340v
  • C 480v
  • D 57600v
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Question 5:
An a.c of 1A at a frequency of 800 cycles per second flows through a coil, the inductance of which is 2.5mH and the resistance of which is 5Ω. What is the power absorbed in the Coil?
  • A 5W
  • B 6W
  • C 7W
  • D 8W
View Answer & Explanation