List of top Physics Questions on Electrostatics

Two infinitely long thin straight parallel wires are kept a perpendicular distance $2R$ having uniform linear charge densities $+\lambda$ and $-\lambda$ respectively. The magnitude of electric field at a mid point between two wires will be ______.

If charge $q$ is placed on one of the vertex of a cube, then total electric flux passing through the cube is ______.

A proton and a $\alpha$-particle are placed in uniform electric field. Accelerations produced in them are $a_p$ and $a_\alpha$ respectively. Then $a_p : a_\alpha$ will be ______.

What is the SI unit of electric flux?

Match List-I with List-II.

Choose the correct answer from the options given below :}

The electrostatic potential in a charged spherical region of radius $r$ varies as $V = ar^{3} + b$, where $a$ and $b$ are constants. The total charge in the sphere of unit radius is $a \times \pi \varepsilon_{0}$. The value of $a$ is ___.
(Permittivity of vacuum is $\varepsilon_{0}$)

Find electric field intensity $ \vec{E} $ at the centre of the circle shown in the figure.

Diagram shows three arrangements of dielectric in a capacitor. Arrange the capacitors in increasing order of capacitance between A and B if $K_1>K_2$.

Two spheres having equal mass $ m $, charge $ q $, and radius $ R $, are moving towards each other. Both have speed $ u $ at an instant when the distance between their centers is $ 4R $. Find the minimum value of $ u $ so that they touch each other.

There are two point charges, one at the vertex and the other at the face of a cube as shown. Find the electric flux through the cube.

A $12\,\text{F}$ capacitor is connected to a $5\,\text{V}$ battery and fully charged. After disconnecting the battery, it is connected in parallel to an uncharged $6\,\text{F}$ capacitor. Find the final charge on the $6\,\text{F}$ capacitor.

In the following configuration of charges. Find the net dipole moment of the system :

If the electric potential is $V = 500$ volts at the point $(10,\,20)$ and the electric field is given by \[ \vec{E} = 10x\,\hat{i} + 5y\,\hat{j}\ \text{N/C}, \] find the potential at the origin.

A parallel plate capacitor with plate separation 5 mm is charged by a battery. On introducing a mica sheet of 2 mm while battery is connected, it is found that it draws 25% more charge. The dielectric constant of mica is :

A simple pendulum with a bob (mass $ m $ and charge $ q $) is in equilibrium in the presence of a horizontal electric field $ E $. Then, the tension in the thread is $ F_1 $. Given $ \frac{F_1}{F_2} = \frac{2}{\sqrt{\alpha}} $, find $ \alpha $.

Three small identical bubbles of water having same charge on each coalesce to form a bigger bubble. Then the ratio of the potentials on one initial bubble and that on the resultant bigger bubble is:

Two small identical metallic balls having charges $ q $ and $ -2q $ are kept far at a separation $ r $. They are brought in contact and then separated at distance $ \frac{r}{2} $. Compared to the initial force $ F $, they will now:

Ten capacitors, each of capacitance $1\,\mu F$, are connected in parallel to a source of $100\,V$. The total energy stored in the system is equal to:

Consider a particle of mass 1 gm and charge 1.0 Coulomb at rest. Now the particle is subjected to an electric field $ E(t)=E_0\sin\omega t $ in the x-direction, where $ E_0=2 $ N/C and $ \omega=1000 $ rad/sec. The maximum speed attained by the particle is

When there is no dielectric, the value of capacitance of a capacitor is $C$. Now some dielectrics are inserted in this capacitor as shown in the diagram. If the new capacitance becomes $\dfrac{nC}{3}$, then find the value of $n$ to the nearest integer

Identify the correct statements:
[A.] Effective capacitance of a series combination of capacitors is always smaller than the smallest capacitance of the combination.
[B.] When a dielectric medium is placed between charged plates of a capacitor, displacement of charges cannot occur due to insulation property of dielectric.
[C.] Increasing area of a capacitor plate or decreasing thickness of dielectric is an alternate method to increase the capacitance.
[D.] For a point charge, concentric spherical shells centered at the location of the charge are equipotential surfaces.
Choose the correct answer from the options given below:

Two point charges of $1\,\text{nC}$ and $2\,\text{nC}$ are placed at two corners of an equilateral triangle of side $3$ cm. The work done in bringing a charge of $3\,\text{nC}$ from infinity to the third corner of the triangle is ________ $\mu\text{J}$. \[ \left(\frac{1}{4\pi\varepsilon_0}=9\times10^9\,\text{N m}^2\text{C}^{-2}\right) \]

The velocity ($v$) – distance ($x$) graph is shown in the figure. Which graph represents acceleration ($a$) versus distance ($x$) variation of this system?

Five positive charges each having charge $q$ are placed at the vertices of a regular pentagon as shown in the figure. The electric potential $V$ and the electric field $\vec{E}$ at the center $O$ of the pentagon due to these five positive charges are

A battery with EMF $E$ and internal resistance $r$ is connected across a resistance $R$. The power consumption in $R$ will be maximum when :