If $q$ is the charge per unit area on the surface of a conductor, then the electric field intensity at a point on the surface is
$\left( {\frac{q}{{{\varepsilon _0}}}} \right)$ normal to surface
$\left( {\frac{q}{{2{\varepsilon _0}}}} \right)$ normal to surface
$\left( {\frac{q}{{{\varepsilon _0}}}} \right)$ tangential to surface
$\left( {\frac{q}{{2{\varepsilon _0}}}} \right)$ tangential to surface
A metallic rod is placed in a uniform electric field. Select the correct option.
Consider an initially neutral hollow conducting spherical shell with inner radius $r$ and outer radius $2 r$. 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 $2 r$ 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
A conducting sphere of radius $10\, cm$ is charged $10\,\mu \,C$. Another uncharged sphere of radius $20\, cm$ is allowed to touch it for some time. After that if the sphere are separated, then surface density of charges, on the spheres will be in the ratio of
The adjacent diagram shows a charge $+Q$ held on an insulating support $S$ and enclosed by a hollow spherical conductor. $O$ represents the centre of the spherical conductor. and $P$ is a point such that $OP = x $ and $SP = r$ . The electric field at point $P$ will be
For the situation shown in the figure below, mark out the correct statement