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Sunday, 21 June 2026
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Physics Past Questions and Answers

Topic: Current Electricity

Jamb Physics Questions - Current Electricity

Question 36:
The maximum permissible current through a galvanometer G of internal resistance 10\(\Omega\) is 0.05A. A resistance R is used to convert G into a voltmeter with a maximum reading of 100V. Find the value of R and how it is connected to G
  • A 20,000 ohms in parallel
  • B 19,990 ohms in series
  • C 1990 ohms in series
  • D 100 ohms in series
View Answer & Explanation
Question 37:
The circuit diagram above contains four ammeters W, X, Y and Z, Which of the following statements about the ammeter readings is correct
  • A The reading of W is equal to that of Y and twice that of X
  • B The reading of Y is greater than that of Z
  • C The readings of W and Y are equal and each is greater than that of X
  • D The reading of Z is equal to the sum of the readings of Y and W
View Answer & Explanation
Question 38:
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
View Answer & Explanation
Question 39:
If a resistance is halved in value and the potential difference across it is tripled, then the ratio of the new current to the old one is
  • A 1 : 6
  • B 1 : 3
  • C 2 : 1
  • D 6 : 1
View Answer & Explanation
Question 40:
If the maximum voltage across a 100ohms resistor is 20V, then the maximum power it can dissipate is
  • A 5.00W
  • B 4.00W
  • C 2.00W
  • D 25W
View Answer & Explanation