Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is
(a) 40Ω
(b) 25 Ω
(c) 250 Ω
(d) 500Ω
Correct option (c) 250 Ω
Explanation:
Let N = number of turns in galvanometer
A = Area, B = magnetic field
k = the restoring torque per unit twist