Four charges of +1$\mu$C, +1$\mu$C, -1$\mu$C and +1$\mu$C are placed at the vertices of a square of side $\sqrt{2}$ cm, in sequence. Net force experienced by 0.1 $\mu$C charge at the center of square

Two short dipoles are placed at a certain distance exert a force 'F' on each other. If the distance between them is doubled then the force will become

The net dipole moment of the system is of the magnitude:

The electric field calculated by Gauss's law is the field due to the charges which:

A small sphere of mass m and having charge q is suspended by a silk thread of length l in a uniform horizontal electric field. If it stands at a distance x from the vertical line from point of suspension, then the magnitude of the electric field is

A pendulum oscillates with the time period T. The string, used in the pendulum, , is stretchable. The point to which it is attached is given a positive charge and the bob is also given positive charge q. The time period of the pendulum will

Two identical small metal spheres having charges q and -3q exert force F on each other. The spheres are touched with each other and then kept at the same separation. The magnitude of the new force between the spheres will be

Two charges 2 $\mathrm{\mu C}$ and 8$\mathrm{\mu C}$ are separated by 6 cm. The neutral point is at:

At what distance from the larger point charge the electric field is zero?

A point charge q is kept at the center of the circle formed by cutting a spherical shell by a plane as shown. The electric flux linked with the remaining surface of the shell is 

In the diagram shown below the block has charge q and is attached at one end of the light spring. The surface is smooth and horizontal and the spring is in its natural length. If the electric field E is switched on, the maximum elongation in the spring will be

A point charge +q is kept at the center of the curvature of thin semicircular wire of length l as shown. The wire has uniformly distributed charge -q on it. The dipole moment of the system is

A conducting body has a cavity in its as shown in the diagram below. A point charge q is held at the centre of the cavity. The electric flux linked with the closed surface S (shown dotted) is

A neutral bubble made of soap solution has radius R. If some negative charge is given which gets distributed uniformly on the surface of the bubble, the radius of the bubble becomes R' then

A large non-conducting sheet S is given a uniform charge density. Two uncharged small, metal rods A and B are placed near the sheet as shown in the following diagram. Then the incorrect option is:

An electric dipole is placed at the centre of a sphere. Which of the following is correct?

A particle with charge +ve and mass m is projected with velocity v in the opposite direction of a uniform electric field E as shown in the figure in a gravity-free space. After what time the velocity will become -v?

Which of the following statements is correct about a dipole in a non-uniform field?

A particle of mass m has a charge $q_0$ when it is at rest. When the particle moves with speed v, the charge on the particle will become (c is the velocity of light in vacuum)

Starting from rest an electron moves through a small distance in a uniform electric field of magnitude $2 \times {10}^4 N{C}^{-1}$. The direction of the field is reserved keeping the magnitude unchanged and a proton moves through the same distance. The time of motion will be

A source charge Q is kept at a distance of 3 km from a test charge $q_0$. If Q is displaced slightly, then the change in the electric field detected by $q_0$ will be after

Two-point charges -q and +9q are kept at r = 12 cm apart as shown. The electric field is zero at:

Two-point charges +2 $\mathrm{\mu C}$ and +6 $\mathrm{\mu C}$ repel each other with a force of 60 N. If a charge -4 $\mathrm{\mu C}$ is added to each of them, the force between them will become

A cone of the radius of base 1 m and height 2 m is placed with its base in the xz plane in a region with the uniform electric field $\overrightarrow{\mathrm{E}} = 20 \hat{\mathrm{i}}$ V/m as shown in the figure. The magnitude of electric flux linked with the cone is

There are two charges 1 $\mathrm{\mu C}$ and 2 $\mathrm{\mu C}$. The ratio of the magnitude of forces acting on them due to their interaction will be

The dielectric constant for the metal in electrostatics is

A cube of side a has a charge q at each of its vertices. The net electric field intensity at its center is: 

( r is the distance between a corner and the center and k = 1/4πε₀ )

The torque acting on an electric dipole of the dipole moment $\overrightarrow{P}$ in a uniform electric field $\overrightarrow{E}$ is

The unit of electric permittivity is

A pendulum bob carries a positive charge. Another positive charge q is held at the point of support, then the time period of bob is (L: length of the simple pendulum)