List of top Physics Questions on Electric charges and fields

An electric dipole of dipole moment $p$ is aligned parallel to a uniform electric field $E$. The energy required to rotate the dipole by $ 90^\circ $ is :
Two identical conducting spheres, fixed in place, attract each other with an electrostatic force of $0.108\,N$ when separated by $50.0\, cm$, center to center. The spheres are then connected by a thin conducting wire. When the wire is removed the spheres repel each other with an electrostatic force of $0.0360\, N$. The initial charges on the spheres were
A non-conducting sphere of radius a has a net charge $+q$ uniformly distributed throughout its volume. A spherical conducting shell having inner and outer, radii b and c and a net charge $-q$ is concentric with the sphere (see the figure). Read the following statements (i) The electric field at a distance $r$ from the center of the sphere = $\frac{1}{4\pi \epsilon_o} \frac {qr}{a^3} for\, r < a$ (ii) The electric field at distance $r$ from the center of the sphere for $a < r < b = 0$ (iii) The electric field at distance $r$ from the center of the sphere for $b < r < c < = 0$ (iv) The charge on the inner surface of the hollow sphere = $-q$ (v) The charge on the outer surface of the hollow sphere = $+q$.
Two parallel metal plates having charges $+ Q$ and $-Q$ face each other at a certain distance between them. If the plates are now dipped in kerosene oil tank, the electric field between the plates will
An electrostatic field line never form closed loop. Electrostatic field is a conservative field.
A cubical region of side a has its centre at the origin. It encloses three fixed point charges, $- q$ at $(0,- \frac{a}{4} ,0), + 3q$ at $(0, 0, 0)$ and $- q$ at $(0,+ \frac{a}{4},0)$. Choose the correct option(s).
A charge $Q$ is enclosed by a Gaussian spherical surface of radius $R$. If the radius is doubled, then the outward electric flux will
An electric dipole is placed in an uniform electric field with the dipole axis making an angle $ \theta $ with the direction of the electric field. The orientation of the dipole for stable equilibrium is
Four charges equal to $-Q$ are placed at the four corners of a square and a charge $q$ is at its centre. lf the system is in equilibrium, the value of $q$ is
Two charges $4q$ and $q$ are placed $3x$ apart in air $A$ charge $Q$ is placed at a point on the line joining so that the systein of these charges remains in equilibrium. Then, the distance of $Q$ from $4q$ and the value of $Q$ are
Among the following, the correct graphical representation of electric intensity as a function of distance from the centre of a uniformly charged conducting sphere is shown in
An electron c penetrates through a thin plate A and enters the electric field region between parallel plates A and B. It gets slowed down Three other particles-proton (p), alpha particles $(\alpha)$ and beta particles $(\beta^-)$ - similarly penetrate through either plate A or plate B as shown. The correct statement as regards the speed of the particles is
A spherical conducting shell of inner radius $r_{1}$ and outer radius $r_{2}$ has a charge $Q$. A charge $-q$ is placed at the centre of the shell. The surface charge density on the inner and outer surfaces of the shell will be
Gauss's law can't be used to calculate electric field near an electric dipole. Electric dipole don't have symmetrical charge distribution.
The unit of physical quantity obtained integral of electric field is
Charge $q_2$ of mass m revolves around a stationary charge $q_1$ in a circular orbit of radius r. The orbital periodic time of $ q_2 $ would be
There exists an electric field of 1 N/C along $Y$ direction. The flux passing through the square of 1 m placed in $XY$ plane inside the electric field is
The total electric flux emanating from a closed surface enclosing an $\alpha$-particle (e = electronic charge) is
A particle of mass $2 \times 10^{-3}$ kg, charge $4 \times 10^{-3}$ C enters in an electric field of 5 V/m, then its kinetic energy after 10 s is
A square surface of side $L$ meter in the plane of the paper is placed in a uniform electric field $E(volt/m)$ acting along the same plane at an angle $q$ with the horizontal side of the square as shown in figure. The electric flux linked to the surface, in units of volt $m$ is
If $ 10^{10} $ electrons are acquired by a body every second, the time required for the body to get a total charge of $1 \,C$ will be
Charges $4Q$ and $Q$ are kept separated by a certain distance and are placed at $A$ and $B$, respectively. Electric intensity at $B $ is $E$. Electric intensity at $A$ is
Electric field produced by an electron at a point is $E$. What will be electric field produced by $Li^{+++}$ at the same point if it is placed at position of electron ?
Two charged spherical conductors of radii $ {{R}_{1}} $ and $ {{R}_{2}} $ are connected by a wire. Then the ratio of surface charge densities of the spheres $ {{\sigma }_{1}}/{{\sigma }_{2}} $ is
Two identical conducting balls $A$ and $B$ have positive charges $q_1$ and $q_2$ respectively but $q_1 \ne q_2$ The balls are brought together so that they touch each other and then kept in their original positions. the force between them is