Q.

For a charged spherical ball, electrostatic potential inside the ball varies with r as V=2ar2+b. Here, a and b are constants and r is the distance from the center. The volume charge density inside the ball is -λaε. The value of λ is _________.  (ε=permittivity of the medium)           [2023]


Ans.

(12)

E=-dVdr=-4arρr3ε0 (compare)

Result inside uniformly charged solid sphere.

ρ=-12aε0

λ=12