`A_(1)` is a spherical conductor of radius (r) placed concentrically inside a thin spherical hollow conductor `A_(2)` of radius (R). `A_(1)` is earthed and `A_(2)` is given a charge `+Q` then the charge on `A_(1)` is -

Options

A. `–Q`
B. `Qr//R`
C. `–rQ//R`
D. `–Q (R–r)//R`

Answer

C

Explanation

`V_(A_(1))=0`
Let `Q_(A_(1))=x`
`(Kx)/(r)+(KQ)/(R)=0`