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 ................. $\Omega$
✓
Answer
d
Current sensitivity
Current sensitivity
$\mathrm{I}_{\mathrm{s}}=\frac{\mathrm{NBA}}{\mathrm{c}}$
Voltage sensitivity
$\mathrm{v}_{\mathrm{s}}=\frac{\mathrm{NBA}}{\mathrm{CR}_{\mathrm{G}}}$
So, resistance of galvanometer
$R_{G}=\frac{l_{s}}{V_{s}}=\frac{5 \times 1}{20 \times 10^{-3}}=\frac{5000}{20}=250\, \Omega$
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