When a resistance of 5 Ω is shunted with a moving coil galvanometer, it shows a full scale deflection for a current of 250 mA , however when 1050 Ω resistance is connected with it in series, it gives full scale deflection for 25 volt. The resistance of galvanometer is _________Ω .

Step-by-step solution

The formula to calculate the maximum current through the galvanometer, when a shunt resistance r 1 is connected is given by i G max = r 1 r 1 + R G i max       . . . 1 When a series resistance r 2 is connected, the potential difference across the galvanometer is given by V = i G max R G + r 2       . . . 2 From equations (1) and (2), it can be written that V = r 1 r 1 + R G i max R G + r 2 ⇒ V r 1 + V R G = i max r 1 R G + i max r 1 r 2 ⇒ V - i max r 1 R G = i max r 1 r 2 -