A galvanometer co

Given:

Resistance of galvanometer coil, G = 15 Ω

Current for full scale deflection, I_g = 4mA

Upper limit of ammeter I = 6A

A galvanometer can detect only small currents and their direction. Thus, to measure large currents it is converted into an ammeter. A galvanometer can be converted into an ammeter by connecting a low resistance called shunt resistance in parallel to the galvanometer

Let shunt resistance = S

We know that value of shunt is given by:

…(1)

By plugging the values of I_g, I and G into Equation (1), we get,

⇒

⇒ S = 10mΩ

For converting the galvanometer into an ammeter of range 0-6 we can add a shunt of resistance 10mΩ.