The half deflection method is used to find out the resistance of a galvanometer. The galvanometer having resistance is connected with resistance R and battery B. The shunt resistance is connected in parallel with the galvanometer.
Apparatus:
A Weston type galvanometer, a voltmeter, a battery or battery eliminator, two (10,000 Ω and 200 Ω) resistance boxes, two one-way keys, a rheostat, a screw gauge, a meter scale, an ammeter of a given range, connecting wires, and a piece of sandpaper.