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Most Important Selected Qs for JEE AdvancedPhysicsElectrostatics

The electrostatic potential inside a charged spherical ball is given by = ^2+b where r is the distance from the centre; a, b are constants. Then the charge density inside ball is

Options

  1. A-6 a ₀ r
  2. B-24 a ₀ r
  3. C-6 a ₀
  4. D24 a ₀ r

Correct answer

C. -6 a ₀

Step-by-step solution

aligned & Potential inside ( )= ar ^2+ b & E _ r =- v r =-2 ar aligned Electric field inside uniformly charged solid volume varies with ' r '. So charge density is constant _ net =(-2 a r) 4 r^2=-8 a r^3 aligned & -8 ar ^3= 4 3 r ^3 ₀ & =-6 a ₀ aligned

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