Consider two concentric conducting spheres of radii `a & b (b gt a)`. Inside sphere has a positive charge ` q_1`. What charge should be given to the outer sphere so that potential of the inner sphere becomes zero ? How does the potential varies between the two spheres `&` outside ?

Explanation

(i) `q_(2)=-(b)/(a)q_(1)`, (ii) `[{:(V_(r)=(q_(1))/(4piepsilon_(0))((1)/(r)-(1)/(a)),,,a lerleb),(V_(b)=(q_(1))/(4piepsilon_(0))((1)/(b)-(1)/(a)),,,r=b),(V_(r)=(1)/(4piepsilon_(0))((q_(1))/(r)+(q_(2))/(r)),,,r geb):}`