KVPY2020PhysicsElectrostatics
Consider a sphere of radius R with unform charged density and total charge Q . The electrostatic potential distribution inside the sphere is given by ϕ ( r ) = Q 4 π ε 0 R a + b ( r / R ) c . Note that the zero of potential is at infinity The values of ( a ,   b ,   c ) are:
Options
- A1 2 , - 3 2 , 1
- B3 2 , - 1 2 , 2
- C1 2 , 1 2 , 1
- D1 2 , - 1 2 , 2
Correct answer
B. 3 2 , - 1 2 , 2
Step-by-step solution
Potential inside uniformly charged solid sphere is given by V = k Q 2 R 3 3 R 2 - r 2 = k Q R 3 R 2 2 R 2 - r 2 2 R 2 = Q 4 π ∈ 0 R 3 2 - 1 2 r R 2 Compare with given formula, i.e, Q 4 π ∈ 0 R a + b r R C a = 3 2 ,   b = - 1 2 , c = 2