Question

A metal conductor of length 1 m rotates vertically about one of its ends at angular velocity 5 rad s^-1. If the horizontal component of earth's magnetic field is 0.2x10^-4 T, the emf developed b/w the ends of the conductor is:
5 microV; 50 microV; 5 mV; 50 mV
Which formula to be used?

Answer 1

Dear Student,

$$\begin{gathered} \mathrm{Motional}\mathrm{emf}\mathrm{between}\mathrm{the}\mathrm{ends}\mathrm{of}\mathrm{conductor}\mathrm{is}, \\ \mathrm{e}=\frac{1}{2}{\mathrm{B\omega L}}^2 \\ \mathrm{or},\mathrm{e}=\frac{1}{2}\times 0.2\times {10}^{-4}\times 5\times {\left(1\right)}^2 \\ \mathrm{or},\mathrm{e}=0.5\times {10}^{-4}=50\mathrm{\mu V} \end{gathered}$$