Question

A potential difference of 600 V is applied across the plates of a parallel plate capacitor. The separation between the plates is 3 mm. An electron projected parallel to the plates as shown with a speed of 2×10⁶ m^-1 moves undeflected between the plates. The magnitude and direction of the magnetic field is

• A. 0.2 T, into the page
• B. 0.2 T, out the page
• C. 1 T, into the page
• D. 0.1 T, out of the page

Answer 1

The correct option is D

0.1 T, out of the page

For no deflection

points from left to right. acts towards positive plate. So must act towards negative plate and hence for this B acts outwards.