A thin spherical conducting shell of radius R has a charge q. Another charge Q is placed at the centre of the shell. The electrostatic potential at a point P a distance `R/2` from the centre of the shell is

A conducting shell of radius R carries charge -Q . A point charge +Q is placed at the centre. The electric field E varies with distance r (from the centre of the shell) as

A spherical shell of radius R has a charge +q units. The electric field due to the shell at a point

A point charge q'q is placed at distance 'a' from the centre of an uncharged thin spherical conducting shell of radius R=2a. A point 'P' is located at a distance 4a from the centre of the conducting shell as shown. The electric potential due to induced charge on the inner surface of the conducting shell at point 'P' is

A point charge Q is placed inside a conducting spherical shell of inner radius 3R and outer radius 5R at a distance R from the centre of the shell. The electric potential at the centre of the shell will be

A metallic spherical shell of radius R has a charge -Q on it. A point charge +Q is placed at the centre of the shell. Which of the graphs shown below may correctly represent the variation of electric field E with distance r from the centre of shell ?