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Saturday, 15 August 2026
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Physics Past Questions and Answers

Topic: (a) Electromagnetic Induction

Jamb Physics Questions - (a) Electromagnetic Induction

Question 21:
The current I in the fig above is
  • A 4.00A
  • B 1.30A
  • C 0.80A
  • D 0.75A
View Answer & Explanation
Question 22:
The primary winding of a transformer has 400 turns and its secondary has 100 turns. If a source of e.m.f. of 12V is applied to the primary, the secondary e.m.f. will be
  • A 3V
  • B 6V
  • C 24V
  • D 48V
View Answer & Explanation
Question 23:
The iron core of an induction coil is made from bundles of wire so as to
  • A Minimize eddy-currents
  • B Generate eddy-current
  • C Prevent sparking at the contact breaker
  • D Get the greatest posible secondary voltage
View Answer & Explanation
Question 24:
A transformer which can produce 8V from a 240v a.c. supply, has an efficiency of 80%. If the current in the secondary coil is 15A, calculate the current in the primary coil.
  • A 0.625A
  • B 1.600A
  • C 2.500A
  • D 6.250A
View Answer & Explanation
Question 25:
The core of an efficient transformer should consist of laminated pieces of metal in order to
  • A Increase the heat produced by increasing the eddy current
  • B Increase the heat produced by reducing the eddy current
  • C Reduce the heat produced by increasing the eddy current
  • D Reduce the heat produced by reducing the eddy current
View Answer & Explanation