JEE Mains 29-Jan-2023 Shift 2 Solved Paper

For a charged spherical ball, electrostatic potential inside the ball varies with r as V=2ar2+b.
Here, a and b are constant 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 medium.
λ=12