A solid conducting sphere has cavity, as shown in figure. A charge $+ {q_1}$ is situated away from the centre. A charge $+q_2$ is situated outside the sphere then true statement is
Charge, distribution on outer surlace of sphere is uniform
Charge, distribution on inner surface of sphere is uniform
Magnitude of force on charge $q_2$ due to induced charge on inner surface of sphere is $\frac{{k{q_1}{q_2}}}{{\left( {\frac{R}{2} + l} \right)}}$
Magnitude of force on charge $q_2$ due to induced charge o n inner surface of sphere is $\frac{{k{q_1}{q_2}}}{{{{\left( l \right)}^2}}}$
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
Explain electrostatic shielding with necessary diagram.
The electric field near a conducting surface having a uniform surface charge density $\sigma $ is given by
$(a)$ A conductor $A$ with a cavity as shown in Figure $(a)$ is given a charge $Q$. Show that the entire charge must appear on the outer surface of the conductor.
$(b)$ Another conductor $B$ with charge $q$ is inserted into the cavity keeping $B$ insulated from $A$. Show that the total charge on the outside surface of $A \text { is } Q+q$ [Figure $(b)$]
$(c)\;A$ sensitive instrument is to be shielded from the strong electrostatic fields in its environment. Suggest a possible way.
Explain electrostatics of conductors. Explain the effects produced inside a metallic conductor placed in an external electric field.