An electron travelling west to east enters a chamber having a uniform electrostatic field in north to south direction . specify the direction in which a uniform magnetic field should be set up to prevent electron from deflecting its straight line path .

Question

$\begin{array}{1 1} 0.5\;mm \\ 0.5\;cm \\ 0.5\;dm \\ 0.5\;m \end{array}$