Galvanometer

Question 1

How is a galvanometer converted to an ammeter?

Answer 1

This is done by connecting a galvanometer in parallel to a low resistance (shunt). Since voltage is constant—

igRg = (i - ig)Rs

Where Rs = resistance of shunt.
I - Ig = current across shunt
Rg= resistance across galvanometer

Question 2

How is a galvanometer converted to a voltmeter?

Answer 2

This is done by connecting the galvanometer in series to a high resistance.

V = ig(R + Rg)

Where R is the needed resistance.