An electric dipole of length $$2 \mathrm{~cm}$$ is placed at an angle of $$30^{\circ}$$ with an electric field $$2 \times 10^5 \mathrm{~N} / \mathrm{C}$$. If the dipole experiences a torque of $$8 \times 10^{-3} \mathrm{~Nm}$$, the magnitude of either charge of the dipole, is

Two long parallel wires kept $$2 \mathrm{~m}$$ apart carry $$3 \mathrm{~A}$$ current each, in the same direction. The force per unit length on one wire due to the other is

Which of the following has its permeability less than that of free space?

A square shaped coil of side $$10 \mathrm{~cm}$$, having 100 turns is placed perpendicular to a magnetic field which is increasing at $$1 \mathrm{~T} / \mathrm{s}$$. The induced emf in the coil is