Two concentric rings of radii `R_(1) = sqrt(6) m` and `R_(2) = 4m` are placed in y-z plane with their centres at origin. They have uniform charge -q and `+ Q = 2 sqrt(2) q` on the inner and outer rings respectively. Consider the electrostatic potential to be zero at infinity. Then

Options

A. a. The electric potential is zero at origin
B. b. The electric field intensity is zero at r = 2m
C. c. A positive charged particle disturbed from origin along the x-axis will restore back to origin.
D. d. Where potential is maximum on the x-axis, field intensity is zero

Answer

B, C, D

Explanation

V at origin `ne =`
`E=(r=2 m)=(K(-q)r)/((R_(1)^(2)+r^(2))^(3//2))+(K.Q.r)/((R_(2)^(2)+r^(2))^(3//2))`
`=K.rq[-(1)/(10^(3//2))+(2 sqrt(2))/(2^(3//2)10^(3//2))]=0`
From origin to r=2, field is towards origin.