A small conducting sphere of radius r is lying concentrically inside a bigger hollow conducting sphere of radius R. The bigger and smaller sphere are charged with Q and q (Q > q) and are insulated from each other. The potential difference between the sphers will be ......
Options:
(a) `1/(4piepsilon_o)(q/r-Q/R)`
(b) `1/(4piepsilon_o)(q/r-q/R)`
(c) `1/(4piepsilon_o)(Q/R+q/r)`
(d) `1/(4piepsilon_o)(q/R-Q/r)`