If magnitude of fourth charge required to be placed at the centre of A to keep the three charges at Q their positions is VK. Find K. -9

A thin metallic spherical shell contains a charge Q on it. A point charge q is placed at the centre of the shell and another charge q_(1) is placed outside it as shown in figure. All the three charges are positive The force on the charge at the centre is

A thin metallic spherical shell contains a charge Q on it. A point charge q is placed at the center of the shell and another charge q_1 is placed outside it as shown in the figure. All the three charges are positive. Find the force on the charge a. at centre due to all charges. b. at center due to shell.

A thin. Metallic spherical shell contains s charge Q on it. A point charge q is placed at the centre of the shell and another charge q_1 is placed outside it as shown in figure (30-Q1). All the three charges are positive. The force on the charge at the centre is

Figure shows a charge q placed at the centre of a hemisphere. A second charge Q is placed at one of the positions A, B, C and D. In which position(s) of this second charge, the flux of the electric field through the hemisphere remains unchanged?

A thin circular wire of radius r has a charge Q. If a point charge q is placed at the centre of the ring, then find the increase in tension in the wire.

Three charges, each of value q, are placed at the corners of an equilateral triangle. A fourth charge Q is placed at the centre O of the triangle. (a) If Q = -q , will the charges at corners starts to move towards centre of away from it. (b) For what value of Q at O will the charges remain stationary ?

A positive charge q is placed in front of cinducting solid cube at a distance d from its centre. Find the electric field at the centre of the cube due to the charges appearing on its surface.