Conductors in Electric Field

A point charge $Q$ is placed at the centre of a spherical conducting shell, the shaded part of the figure. A total charge of $-q$ is placed on the shell. The magnitude of the electric field at point $P_1$ at a distance $R_1$ from the centre and the magnitude of the electric field at point $P_2$ a distance $R_2$ from the centre are respectively

A system consists of three concentric metal shells $A$, $B$ and $C$ with radii $a, 2a$ and $3a$ respectively. Shell $B$ is connected to earth and outermost shell is given a charge $Q$. Now if shell $C$ is connected to shell $A$, then the final charge on the shell $B$ is $\frac{-Qx}{11},$ then find the value of $x$.

There are three concentric conducting spherical shells. All of them are charged $Q_1=20 \mathrm{C}$, $Q_2=40 \mathrm{C}, Q_3=60 \mathrm{C}$ and radius $R, 2R, 3R$. The innermost sphere is earthed then find the magnitude of charge transfer from the Earth.

Two concentric conducting thin shells of radius $R$ and $2 R$ carry charges $+Q$ and $+3 Q$ respectively. The magnitude of electric field at a distance $x$ outside and inside from the surface of outer sphere is same. Then the value of $x$ is:-

Two conducting, concentric, hollow spheres $A$ and $B$ have radii $a$ and $b$ respectively, with $A$ inside $B.$ They have the same potential $V.$ A is now given some charge such that its potential becomes zero. The potential of $B$ will now be

A spherical shell with an inner radius $\text{'}\mathrm{a}\text{'}$ and an outer radius $\text{'}\mathrm{b}\text{'}$ is made of conducting material. A point charge $+\mathrm{Q}$ is placed at the centre of the spherical shell and a total charge $-\mathrm{q}$ is placed on the shell. Final charge distribution on the surfaces as:

When a positively charged conductor is connected to earth,

Which statement is not correct?

A spherical shell with an inner radius $\text{'}a\text{'}$ and an outer radius $\text{'}b\text{'}$ 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

Two large conducting sheets are kept parallel to each other as shown. In equilibrium, the charge density on facing surfaces is ${\sigma }_1$ and ${\sigma }_2.$ Which of the following may not be electric field at $A:\mathit{-}$

Three concentric metallic spherical shells of radii $R, 2 R, 3 R$ are given charges $Q_1,Q_2,Q_3,$ respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells, $Q_1:Q_2:Q_3$, is:-

The figure shows a charge q placed inside a cavity in an uncharged conductor. Now if an external electric field is switched on:

Find the charge on both surfaces of middle metal plate.

$A_1$ is a spherical conductor of radius $\left(r\right)$ placed concentrically inside a thin spherical hollow conductor $A_2$ of radius $\left(R\right).A_1$ is earthed and $A_2$ is given a charge $+Q$ then the charge on $A_1$ is -

A charge $Q$ is distributed over two concentric hollow spheres of radii $\left(r\right)$ and $\left(R\right)>\left(r\right)$ such that the surface densities are equal. Find the potential at the common centre.

There concentric metallic spherical shells of radii $R, 2R, 3R$ are given charges $Q_1, Q_2, Q_3,$ respectively. It is found that the surface charge densities on the outer surface of the shells are equal. Then, the ratio of the charges given to the shells, $Q_1, Q_2, Q_3,$ is :

Can electric field at some point be zero though electric potential is not zero? Give example.

The internal and external pressures for a soap bubble are same. The surface tension of soap solution is $0.04 \mathrm{N}/\mathrm{m}$ and its diameter is $4 \mathrm{cm}$. Determine the charge on soap bubble.

Establish expression for maximum charged density for the equilibrium of a charged soap bubble in a vacuum.