-->

Moving Charges And Magnetism

Question
CBSEENPH12040168

To reduce the range of voltmeter, its resistance needs to be reduced. A voltmeter has resistance Ro and ranges V. Which of the following resistances when connected in parallel will convert it into a voltmeter of range V/n?

  • nR0

  • (n+1)R0

  • (n-1)R

  • None of these

Solution

D.

None of these

When a resistance is connected in parallel, it reduces the resistance of combination but the range is not reduced. For the purpose of reducing the range the resistance in series with galvanometer need to be reduced.

This cannot be achieved by connecting a resistance in parallel with a voltmeter. It should be noted that the range of voltmeter can only be increased but cannot be decreased.