A thin, uniformly charged ring of radius $R$ carries a total charge $Q$. A point charge $q$ is placed at the center of the ring. The force required to move the charge $q$ a small distance $z$ along the axis of the ring is proportional to:

Two point charges + 8q and -2q are located at $x = 0$ and $x = L$ respectively. The location of a point on the $x$- axis at which the net electric field due to these two point charges is zero is

What is the magnitude of a point charge due to which the electric field 30cm away has the magnitude $2\;newton/coulomb$ $[1/4\pi {\varepsilon _0} = 9 imes {10^9}N{m^2}/{C^2}]$

A force of 2.25 N acts on a charge of $15 imes {10^{ - 4}}$. Calculate the intensity of electric field at that point

Which of the following statement is correct?

A spherical conductor has a radius of $5$ cm and a uniformly distributed charge of $8 imes 10^{-8}$ C. What is the magnitude of the electric field at a distance of $15$ cm from the center of the sphere? (Assume $\frac{1}{4\pi\epsilon_0} = 9 imes 10^9 Nm^2/C^2$).

A force of 2.25 N acts on a charge of $15 imes {10^{ - 4}}$. Calculate the intensity of electric field at that point

What is the SI unit of electric field?

If the linear charge density of a cylinder is $4\mu C{{\rm{m}}^{ - 1}}$ then electric field intensity at point $3.6{\rm{ }}\;cm$ from axis is

A ring of radius $r$ carries a charge $Q$ uniformly distributed over its length. A charge $q$ is placed at its centre will experience a force equal to

A charge $q$ is placed at centre of the line joining two equal charges Q. The system of 3 charges will be in equilibrium of $q$ is equal to