0

I have learned that charges inside a conductor align themselves in an external field such that the net electric field inside them is always zero. My teacher taught me that most concepts of gravitation and electrostatics are similar. For example, the expressions of force due to two charges or two masses, but I came across this question:

question

If a similar question was asked given a spherical shell and a charge $q$ in its proximity, the answer would be that the electric field is zero but not electric potential. But the answer to (the question i have attached) was option (D). Can someone give me an intuitive explanation of why here the two topics come out to be different?

Andrew
  • 813
Aman Nambisan
  • 25

1 Answers1

1

If a conducting spherical shell is placed in the field of an external charge, the free electrons in the conductor will shift position until the is no resultant field in the conductor. With no field, all points in the conductor must have the same potential. With all points on the inner surface of the conductor at the same potential, there can be no field (in the hollow space inside) connecting any two such points.
When talking about a gravitational field, it is assumed that the masses which produce the field cannot shift their position. (The sphere acts like a non-conductor.)

R.W. Bird
  • 12,139