A conducting sphere with inner radius R and outer radius 3R has some alloys mixed in it due to which its resistivity changes with radial distance r according to the function P = Kr, where K is a +ve constant. Inner surface of the sphere is grounded while outer surface of sphere in maintained at potential Vo with the help of a battery of emf Vo. Battery is ideal. The potential of the sphere at radial distance of 2R is V in a (n b Find (a + b). 7 L 3R Lit -Vo