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A hollow insulated conduction sphere is given a positive charge of 10 µC. What will be the electric field at the centre of the sphere if its radius is 2 metres?
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- zero
- 5 µCm–2
- 20 µCm–2
- 8 µCm–2
Correct Option: A
Charge resides on the outer surface of a conducting hollow sphere of radius R. We consider a spherical surface of radius r < R.
By Gauss's theorem,
| ∮E→ . ds→ = | × charge enclosed | |
| ε0 |
| or E.4πr2 = | × 0 ⇒ E = 0 | |
| ε0 |
i.e. electric field inside a hollow sphere is zero.
