electrostatics Questions

An electric dipole is placed at an angle of $30^{\circ }$ with an electric field of intensity $2\times 10^5{\text{N C}}^{-1}$. It experiences a torque equal to $4\text{Nm}$. Calculate the magnitude of charge on the dipole, if the dipole length is $2\text{cm}$.

An electric dipole is placed as shown in the figure. The electric potential (in $10^2\text{V}$) at point P due to the dipole is ($K=\frac{1}{4\pi {ϵ}_0}$):

The equivalent capacitance of the system shown in the following circuit is:

If ${\oint }_S\vec{E}\cdot d\vec{S}=0$ over a surface, then: