Current senstivity of moving coil galvanometer is `5 "div"//mA` and its voltage senstivity (angular deflection per unit voltage applied) is `20 "div"//V`. The resistance of the galvanometer is

Options

A. `40 Omega`
B. `25 Omega`
C. `250 Omega`
D. `500 Omega`

Answer

C

Explanation

Current sensitivity `theta/i=5/10^(-3)=5000"div"/A …(i)`
Velocity sensitivity `theta/V=20`
From (i)//(ii), we get `(theta//i)/(theta//V)=5000/10=250`
`implies V/i=R=250 Omega`