A current carrying wire $PQ$ is placed $ \perp$ to another wire $RS$ carrying a constant current. If the second wire is free to move, it will have

Question

 

$\begin {array} {1 1} (a)\;Translational\: motion\: only & \quad (b)\;Rotational\: motion \: only \\ (c)\;No\: motion\: at\: all & \quad (d)\;Both\: translational\: and\: rotational \: motion \end {array}$