Question

To convert a galvanometer into a voltmeter one should connect a

(a) high resistance in series with galvanometer

(b) low resistance in series with galvanometer

(c) high resistance in parallel with  galvanometer 

(d) low resistance in parallel with galvanometer.

Answer 1

Correct option  (a) high resistance in series with galvanometer

Explanation:

voltmeter is used to measure the potential difference across a resistance and it is connected in parallel with the circuit. A high resistance is connected to the galvanometer in series so that only a small fraction (l ) of the main circuit current (l_g) passes through it. If a considerable amount of current is allowed to pass through the voltmeter, then the reading obtained by this voltmeter will not be close to the actual potential difference between the same two points.