Question

How is a galvanometer converted into an ammeter?

(a) By connecting a high resistance shunt in parallel to the galvanometer

(b) By connecting a low resistance shunt in parallel to the galvanometer

(c) By connecting a high resistance shunt in series with the galvanometer

(d) By connecting a low resistance shunt in series with the galvanometer

This question was addressed to me in unit test.

This key question is from Moving Coil Galvanometer in division Moving Charges and Magnetism of Physics – Class 12

Answer 1

The correct choice is (b) By connecting a low resistance shunt in parallel to the galvanometer

Easiest explanation: A galvanometer can be converted into an ammeter of given range by connecting suitable low resistance S called shunt in parallel to the given galvanometer, whose value is given by:

S = \( [ \frac {I_g}{(I – I_g)} ] \)G

Where Ig is the current for full scale deflection of galvanometer, I is the current to be measured by the galvanometer and G is the resistance of galvanometer.