A potential difference of 800 V is applied across the plates of a parallel plate capacitor. The separation between the plates is 5 mm and a uniform…

A potential difference of $\displaystyle 800$ V is applied across the plates of a parallel plate capacitor. The separation between the plates is $\displaystyle 5$ mm and a uniform magnetic field is applied parallel to the plates horizontally. An electron projected vertically parallel to the plates, with a velocity of $\displaystyle 2 \times 10^6 \mathrm{~m} / \mathrm{s}$ moves undeflected between the plates. The magnitude of the magnetic field will be \_\_\_\_$\displaystyle \times 10^{-2} \mathrm{~T}$.