Question

If a proton is placed at one of the three points above, which of the following statement is true?

• A. The proton will experience a greater force at point I than at point II
• B. The proton will experience a greater force at point II than at point I
• C. The proton will experience a greater force at point III than at point II
• D. The proton will experience the same force at point I, II and III
• E. The proton will experience no force at point I

Answer 1

The correct option is D The proton will experience the same force at point I, II and III

Due to the applied potential difference across the plates with distance, say $d$, between them, an electric field exists between them with magnitude $\frac{V}{d}$ which is uniform at all points.

The force acting on a proton placed between the plates is $qE$, which is independent of the location of the charge. Hence the proton experiences equal amount of force at all three points.