Two concentric coplanar rings one of radius a and the other of radius 2a, have charges qa and qb respectively. A charged particle is in equilibrium on their common axis at a distance a from the common centre. Then the ratio qa/qb is

Two concentric rings, one of radius a and the other of radius b, have the charges +q, and -(2//5)^(-3//2)q , respectively as shown in fig. Find the rario b//a if a charge particle palaced on the axis at z =a is i equilibrium.

Two concentric rings, one of radius a and the other of radius b, have the charges +q, and -(2//5)^(-3//2)q , respectively as shown in fig. Find the rario b//a if a charge particle palaced on the axis at z =a is i equilibrium.

Two concentric rings, one of radius a and the other of radius b, have the charges +q, and -(2//5)^(-3//2)q , respectively as shown in fig. Find the rario b//a if a charge particle palaced on the axis at z =a is i equilibrium.

Two concentric rings, one of radius R and total charge +Q and second of radius 2R and total charge -sqrt(8)Q , lie in x-y plane (i.e., z=0 plane). The common centre of rings lies at origin and the common axis coincides with z -axis. The charge is uniformly distributed on both rings. At what distance from origin is the net electric field on z -axis zero?

Two concentric rings, one of radius R and total charge +Q and second of radius 2R and total charge -sqrt(8)Q , lie in x-y plane (i.e., z=0 plane). The common centre of rings lies at origin and the common axis coincides with z -axis. The charge is uniformly distributed on both rings. At what distance from origin is the net electric field on z -axis zero?

Potential on the axis of ring of radius 3R and at distance 4R from centre of ring is (charge on the ring is Q )

A ring of radius R is carrying uniformly distributed charge +Q . A test charge -q_0 isplaced on its axis at a distance 2R from the centre and released. The motion of the particle on the axis will be :

A ring has radius 30cm and a charge of 2nC .The electric potential on the axis of the ring at a distance of 40cm from its centre will be

A ring of radius a contains a charge q distributed. uniformly ober its length. Find the electric field at a point. on the axis of the ring at a distance x from the centre.