If charge q is induced on outer surface of sphere of radius R, then intensity at a point P at a distance S from its centre is

If sigma is surface density of charge on the charged cylinder of radius R, then electric intensity E at outer point at a distance r from its axis is

A sphere of radius R has a charge density sigma . The electric intensity at a point at a distance r from its centre is

If radius of a hollow metallic sphere is .R.. If the P.D between it.s surface and a point at a distance 3R from it.s centre is V then the electric field intensity at a distance 3R from it.s centre is

There is a cubical cavity inside a conducting sphere of radius R. A positive point charge Q is placed at the centre of the cube and another positive charge q is placed at a distance 1(gtR) from the centre of the sphere. The sphere is earthed Net charge on the outer surface of conducting sphere is

Consider an initially neutral hollow conducting spherical shell with inner radius r and outer radius 2r. A point charge +Q is now placed inside the shell at a distance r/2 from the centre. The shell is then grounded by connecting the outer surface to the earth. P is an external point at a distance 2r from the point charge +Q on the line passing through the centre and the point charge +Q as shown in the figure. The magnitude of the force on a test charge +q placed at P will be