A galvanometer has a resistance of 30 ohm and a current of 2 mA is needed to give a full scale deflection. What is the resistance needed and how is it to be connected to convert this galvanometer
(a) Into an ammeter of 0.3 A range ?
(b) Into a volmeter of 0.2 V range ?

Explanation

(a) to convert galvanometer intio ammeter a shunt has to be connected in parallel to the galvanometer.
Thus `2xx10^(-3)R_(G)=(0.302xx10^(-3))r_(s)`

`r_(s)=(2xx10^(-3)xx30)/0.3=0.2Omega`
(b) To convert galvanometer into voltmeter a resistance has to be connected in series
`implies2xx10^(-3)(R_(G)+R)=0.2`
`implies30+R=100`
`impliesR=70Omega`