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Thursday, 30 July 2026
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Physics Past Questions and Answers

Jamb 1993 Physics Questions

Question 31:
A 40-W instrument has a resistance of 90\(\Omega\). On what voltage should it be operated normally?
  • A 60V
  • B 150V
  • C 225V
  • D 3600V
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Question 32:
Which of the following devices may be used to step up the voltage in a d.c. circuit?
  • A A step-up transformer
  • B A d.c. generator
  • C A wattmeter
  • D An induction coil
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Question 33:
The primary aim in high tension transmission is to
  • A Minimize electrical energy losses due to heat production
  • B Increase the rate of energy transfer by using high voltage
  • C Increase the current in the wire
  • D Generate electricity at high current and low voltage
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Question 34:
Determine the inductive reactance when a 30.0mH inductor with a negligible resistance is connected to a 1.3 x 103Hz oscillator.
  • A 39.0\(\Omega\)
  • B 122.5\(\Omega\)
  • C 245.0\(\Omega\)
  • D 39000.0\(\Omega\)
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Question 35:
Which of the following statements correctly describe(s) cathode rays? i. they consist of tiny particles carrying negative electric charges. ii. they are deflected in a magnetic field but not in an electric field. iii. they consist of fast moving neutrons and deflected in an electric field.
  • A I only
  • B Ii only
  • C I and ii only
  • D Ii and iii only
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