A potential difference of 600 V is applied across the plates of a parallel plate condenser. The separation between the plates is 3 mm. An electron projected vertically, parallel to the plates, with a velocity of 2×106 ms-1 moves undeflected between the plates. Find the magnitude of the magnetic field in the region between the condenser plates. (Neglect the edge effects. Charge of the electron= -1.6×10−19C )