Question

Consider a galvanometer with a full scale deflection of 1 m A and resistance 100Ω.

1. How is the device connected in the circuit?

2. How can it be converted to an ammeter with full scale deflection 1 ampere?

Answer 1

1. Connected in series.

2. S = \(\frac{Ig\,G}{I-Ig}\)

= \(\frac{1\times10^{-3}\times 100}{1-1\times 10^{-3}}\) = \(\frac{0.1}{1-0.001}\) = \(\frac{1}{.999}\) = 0.1Ω

by connecting a shunt resistance. 0.1Ω in parallel with galvanometer, we can convert galvanometer in to ammeter.