A thin metallic spherical shell of radius R carries a charge Q on its surface. A point charge ` (Q)/(2) ` is placed at its centre C and another charge +2Q is placed outside the shell at point A at a distance x from the centre `(x gt R) `
Find the force on the charge at the centre of the shell and at the point A
Find the electric flux through the shell.

Explanation

The force on the charge `(Q)/(2) ` placed at the centre of shell is zero because electric field point C , inside the shell is zero.
For the purpose of electric force on charge 2Q placed at point A.
the charge Q present on spherical shell may be considered to be
` therefore `Force at point A, `F_A=(1)/(4piin _0) .((3Q//2)(2Q))/(x^(2)) =(1)/(4piin _0) .(3Q^(2))/(2) `
(b) Electric flux through the shell `phi_in =(1)/(in_0) `(charged enclosed ) `=(1)/(in_0) .(3Q)/(2) =(3Q)/(2in_0) `
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