JEE Main20198 Apr 2019Morning ShiftPhysicsElectrostaticsActual
A solid conducting sphere, having a charge Q , is surrounded by an uncharged conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be V . If the shell is now given a charge of – 4 Q , the new potential difference between the same two surfaces is:
Options
- A– 2 V
- B2 V
- CV
- D4 V
Correct answer
C. V
Step-by-step solution
First condition: Both conducting spheres are shown. V i n - V o u t = K Q r 1 - K Q r 2 ⇒ V = K Q 1 r 1 - 1 r 2 Second condition: Shell is now given charge - 4 Q . V i n - V o u t = K Q r 1 - 4 K Q r 2 - K Q r 2 - 4 K Q r 2 = K Q r 1 - K Q r 2 = K Q 1 r 1 - 1 r 2 = V