Question

In an isolated parallel - plate capacitor of capacitance C, the four surfaces have charges $Q _ { 4 }$ as shown. The potential difference between the plates is

• A.
• B.
• C.
• D.

Answer 1

Answer: (C)

Answer 2

Plane conducting surfaces facing each other must have equal and opposite charge densities. Here, as the plate areas are equal, Q₂ = - Q₃

The charge on a capacitor means the charge on the inner surface of the positive plate - (in this case Q₂)

Potential difference between the plates

= charge on the capacitor ÷ capacitance.

∴ Potential difference

=