A shunt of resistance $1 ~\Omega$ is connected across a galvanometer of $120 ~\Omega$ resistance. A current…
A shunt of resistance $1 ~\Omega$ is connected across a galvanometer of $120 ~\Omega$ resistance. A current of $5.5$ ampere gives full scale deflection in the galvanometer. The current that will give full scale deflection in the absence of the shunt is nearly :
$5.5$ ampere
$0.5$ ampere
$0.004$ ampere
$0.045$ ampere
Solution
The current that will given full scale deflection in the absence of the shunt is nearly equal to the current through the galvanometer when shunt is connected i.e. $\mathrm{I}_{\mathrm{g}}$
As $I_g=\frac{I S}{G+S}$
$=\frac{5.5 \times 1}{120+1}=0.045$ ampere