For a moving coil galvanometer, the deflection in the coil is 0.05 rad when a current of 10 mA is passed through it. If the torsional constant of…

For a moving coil galvanometer, the deflection in the coil is $\displaystyle 0.05$ rad when a current of $\displaystyle 10$ mA is passed through it. If the torsional constant of suspension wire is $\displaystyle 4.0 \times 10^{-5} \mathrm{~N} \mathrm{~m} \mathrm{rad}^{-1}$, the magnetic field is $\displaystyle 0.01$ T and the number of turns in the coil is $\displaystyle 200$ , the area of each turn (in $\displaystyle \mathrm{cm}^2$ ) is :