Assertion : A metallic shield in form of a hollow shell may be built to block an electric field.
Reason : In a hollow spherical shield, the electric field inside it is zero at every point.
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
If the Assertion is correct but Reason is incorrect.
If both the Assertion and Reason are incorrect.
A charge $q$ is distributed uniformly on the surface of a sphere of radius $R$. It is covered by a concentric hollow conducting sphere of radius $2 R$. Charge on the outer suiface of the hollow sphere will be, if it is earthed
Assertion : In a cavity within a conductor, the electric field is zero.
Reason : Charges in a conductor reside only at its surface
‘At the surface of a charged conductor electrostatic field must be normal to the surface at every point’. Explain.
Four metal conductors having different shapes
$1.$ A sphere $2.$ Cylindrical
$3.$ Pear $4.$ Lightning conductor
are mounted on insulating stands and charged. The one which is best suited to retain the charges for a longer time is
Aspherical shell with an inner radius $'a'$ and an outer radius $'b' $ is made of conducting material. A point charge $+Q$ is placed at the centre of the spherical shell and a total charge $- q $ is placed on the shell.
Charge $- q $ is distributed on the surfaces as