Question

14. A point change Q is at the centre of a conducting shell and another charge q is outside the shell. Now answer the following: Does the charge Q experience a force? ii) Does the charge q experience a force? Explain​

Answer 1

Conductors

• Whenever any conductor is placed in external electric field, the electrons inside it will shift in such a way, that one of the side become deficient of electrons while other at excess.
• This shifting (induction) creates a induced electric field inside the conductor.
• Induced EF is in opposite to direction of ext EF.
• And by continuous shifting of electrons and increased in induce EF, one ìnstant (electrostatic equilibrium) will come when $\rm E_{induced} = E_{ext}$
• This results to be inside electric field to be always zero.

☆ Conductors have a unique property of maintaining zero electric field inside.(if no inside charge initially)

Solution:

(i) Does the charge Q experience a force?

1. The electric field produced by 'q' will have no effect on conductor.
2. EF by q inside conductor = 0
3. That means Charge Q will be shielded by outside EF (Shielding effect)

• Since no effect by EF by q results in no force experience.

• Charge Q will not experience force .

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(ii) Does the charge q experience a force?

1. conductor will emit the electric field of Q
2. Since it is placed inside initially, having some initial electric field.

• EF produced will be as of point charge by Q

• Yes, charge q will experience force.

• $\ F = \dfrac { KqQ}{r^2}$

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