Question

A metal spherical shell has an inner radius `R_(1)` and outer radius `R_(2)`. A charge Q is placed at the center of the spherical cavity. What will be surface charge density on (i) the inner surface, and (ii) the outer surface ?

Answer 1

Here, the charge placed at the centre of the spherical cavity is positively charged. So, the charge created at the inner surface of the sphere due to induction will be -Q and due to this charge created at outer surface of the sphere is +Q.
Now, surface charge density ont he inner surface `=(-Q)/(4piR_(1)^(2))` and
Surface charge density on the inner surface `=(+Q)/(4piR_(2)^(2))`
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