A moving coil galvanometer gives full scale defection when a current of 0.05 A is passed through its coil it is converted in to a voltmeter reading up to 5V by using an external resistance of 975 `omega` what is the resistance of the galvanometer coil ?

Options

A. `30 Omega`
B. `25 Omega`
C. `50 Omega`
D. `40 Omega`

Answer

B

Explanation

Here `i_(g)=0.005 A, V=500 V, R=965 omega , G=?`
we have `R=(V)/(i_(g))-G`
or the resistance of the gavanometer coil
`G=(V)/(i_(g))-R=(5)/(0.005)-975 =25 omega`