A rectangular loop $PQMN$ with movable arm $PQ$ of length $10 \mathrm{cm}$ and resistance $2 \mathrm{\Omega }$ is placed in a uniform magnetic field of $0.1 \mathrm{T}$ acting perpendicular to the plane of the loop as is shown in the figure. The resistances of the arms $MN$, $NP$ and $MQ$ are negligible. Calculate the current induced in the loop when arm $PQ$ is moved with velocity $20 \mathrm{m} {\mathrm{s}}^{-1}$.