Q.

Consider a circular loop that is uniformly charged and has a radius a2. Find the position along the positive z-axis of the cartesian coordinate system where the electric field is maximum if the ring was assumed to be placed in xy-plane at the origin:          [2025]

1 a2  
2 a2  
3 a  
4 0  

Ans.

(3)

E=KQr(x2+R2)3/2

For Emax,dEdx=0

 x=R2=2a2=a