A point charge q produces an electric field of magnitude $2N{C}^{-1}2\; \backslash \; N\; \backslash \; C^\{-1\}$ at a point distance 0.25 m from it. What is the value of charge?

The electric intensity in air at a point 20 cm from a point charge Q coulombs is $4.5\times {10}^{5}N\mathrm{/}C\mathrm{.}4.5\; \backslash times\; 10\; ^5\; \backslash ,\; N/C.$ The magnitude of Q is

The charge on the electron is $1.6\times {10}^{-19}C\mathrm{.}1.6\; \backslash times\; 10\; ^\{-19\}\; C.$ The number of electrons need to be removed from a metal sphere of 0.05 m radius so as to acquire a charge of $4\times {10}^{-15}C4\; \backslash times\; 10\; ^\{-15\}\; C$ is

Electric lines of force about a positive point charge and negative point charge are respectively .

Which of the following is NOT the property of equipotential surfaces?

In a uniform electric field, a charge of 3 C experiences a force of 3000 N. The potential difference between two points 1 cm apart along the electric lines of force will be

Gauss’ law helps in

An electric dipole of moment p is placed in the position of stable equilibrium in a uniform electric field of intensity E. The torque required to rotate, when the dipole makes an angle $\theta \backslash theta$ with the initial position is

Four coulomb charge is uniformly distributed on 2 km long wire. Its linear charge density is

The electric flux over a sphere of radius 1.0 m is $\varphi \backslash phi$. If the radius of the sphere is doubled without changing the charge, the flux will be