Question

a resistance of 900 ohm is connected in series with a galvanometer of resistance 100 ohm . A potential difference of 1 volt produces 100 division deflection in the galvanometer .Find the figure of merit of galvanometer​

Answer 1

Given that,

Resistance, R₁ = 900 ohms

Resistance, R₂ = 100 ohms

A potential difference of 1 volt produces 100 division deflection in the galvanometer.

To find,

The figure of merit of the galvanometer​.

Solution,

If a coil is placed in a radial magnetic field, it experiences a deflection θ such that,

I = kθ

k is constant of proportionality and is termed as figure of merit of the galvanometer.

$k=\dfrac{I}{\theta}$

Since, $I=\dfrac{V}{R}$

So,

$k=\dfrac{1}{(900+100)\times 100}\\\\k=10^{-5}\ \text{A}/\text{division}$

Hence, the figure of merit of the galvanometer is $10^{-5}\ \text{A}/\text{division}$.