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

Question

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) 500 Ω (B) 40 Ω (C) 250 Ω (D) 25 Ω

Tardigrade Admin · Accepted Answer

Current sensitivity IS = (NBA/C) Voltage sensitivity VS = (NBA/CRG) So, resistance of galvanometer RG = (IS/VS) = (5 × 1/20 × 10-3) = (5000/20) = 250 Ω

Q. Current sensitivity of a moving coil galvanometer is $5 d i v / m A$ and its voltage sensitivity (angular deflection per unit voltage applied) is $20 d i v / V$ . The resistance of the galvanometer is

$500 Ω$

$40 Ω$

$250 Ω$

$25 Ω$

Current sensitivity
$I_{S} = \frac{NB A}{C}$
Voltage sensitivity
$V_{S} = \frac{NB A}{C R _{G}}$
So, resistance of galvanometer
$R_{G} = \frac{I _{S}}{V _{S}} = \frac{5 \times 1}{20 \times 1 0 ^{- 3}} = \frac{5000}{20} = 250 Ω$

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

500Ω

40Ω

250Ω

25Ω