Question

For full scale deflection of total $50$ divisions, $50\text{mV}$ voltage is required in galvanometer. The resistance of galvanometer if its current sensitivity is $2\text{div/mA}$ will be :

• A. $5\Omega$
• B. $2\Omega$
• C. $1\Omega$
• D. $4\Omega$

Answer 1

The correct option is B $2\Omega$

Let the resistance of the galvanometer is $R$.
The maximum current that can flow through the galvanometer is :
$I_{max}=\frac{50}{2}=25\text{mA}$
Therefore, the resistance of the galvanometer is :
$R=\frac{50}{25}=2\Omega$