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Sunday, 21 June 2026
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Physics Past Questions and Answers

Topic: Electromagnetic Induction

Jamb Physics Questions - Electromagnetic Induction

Question 41:
Which of the following operations can be used to convert an alternative current dynamo into a direct current dynamo
  • A Number of turns in the coil is increased
  • B Strength of the field magnet is increased
  • C Slip rings are replaced with split ring cummutator
  • D Coil is wound on a soft iron armature
View Answer & Explanation
Question 42:
An alternating current can induce voltage because it has
  • A Ripple value
  • B Varying magnetic field
  • C Weaker magnetic field than direct current
  • D High peak value
View Answer & Explanation
Question 43:
A coil X is moved quickly away from the end Y of a stationary metal bar and a current then flows in X as shown above.
Then
  • A The bar is not a magnet
  • B Y is a north pole
  • C Y is a South pole
  • D Y repels coil X
View Answer & Explanation
Question 44:
A transformer has 300 turns of wire in the primary coil and 30 turns in the secondary coil. If the input voltage is 100 volts, the output voltage is
  • A 5 volts
  • B 10 volts
  • C 15 volts
  • D 20 volts
View Answer & Explanation
Question 45:
Which expression gives magnetic flux?
  • A QVB sin\(\theta\)
  • B \(\frac{\mu \phi I}{2 \pi r}\)
  • C BA cos \(\theta\)
  • D -N \(\frac{d \phi}{dt}\)
View Answer & Explanation