An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is

Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.

Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.

Rank the electrostatic potential energies for the given system of charges in increasing order

A parallel plate capacitor stores a charge Q at a voltage V. Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?

Write the general definition of electric dipole moment for a collection of point charge.

What are the properties of an equipotential surface?

Give the relation between electric field and electric potential.

What are Polar molecules? Give examples.

Two small-sized identical equally charged spheres, each having mass 1 g are hanging in equilibrium as shown in the figure. The length of each string is 10 cm and the angle θ is 30° with the vertical. Calculate the magnitude of the charge in each sphere. (Take g = 10 ms⁻²)

A sample of HCl gas is placed in a uniform electric field of magnitude 3 x 10⁴ NC^-1. The dipole moment of each HCl molecule is 3.4 x 10^-30 Cm. Calculate the maximum torque experienced by each HCl molecule.

(a) Calculate the electric potential at points P and Q as shown in the figure below.
(b) Suppose the charge + 9μC is replaced by - 9 μC find the electrostatic potentials at points P and Q.

(c) Calculate the work done to bring a test charge +2 μC from infinity to the point Q. Assume the charge +9 μC is held fixed at origin and +2 μC is brought from infinity to P.

Write the special features of Gauss law.

What is dielectrics or insulators.

Four charges are arranged at the corners of the square PQRS of side an as shown in the figure.
(a) Find the work required to assemble these charges in the given configuration.
(b) Suppose a charge q is brought to the center of the square, by keeping the four charges fixed at the corners, how much extra work is required for this?

A water molecule has an electric dipole moment of 6.3 x 10^-30 Cm. A sample contains 10²² water molecules, with all the dipole moments aligned parallel to the external electric field of magnitude 3 x 10⁵ NC^-1. How much work is required to rotate all the water molecules from θ = 0° to 90°? 

A small ball of conducting material having a charge +q and mass m is thrown upward at an angle θ to horizontal surface with an initial speed v_o as shown in the figure. There exists an uniform electric field E downward along with the gravitational field g. Calculate the range, maximum height and time of flight in the motion of this charged ball. Neglect the effect of air and treat the ball as a point mass.

A polythene piece rubbed with wool is found to have a negative charge of 3 x 10^-7 C. Estimate the number of electrons transferred from which to which?