The electrical field strength at a distance point A due to a point charge +q, located at the origin, is 100 µl v/m. If the point charge is now enclosed by a perfectly conducting metal sheet sphere whose centre is at origin, A, outside the sphere, becomes

• A.  - 100 μ v/m.
• B.  0.
• C.  None of above.
• D.  100 μ v/m.

Answer: (D)