The unit $Volt/metre$ is the unit of:

Two point charges $-10 \mu C$ and $+5 \mu C$ are situated on the $X$-axis at $x=0$ and $x=\sqrt{2} \ m$. The point along the $X$-axis where the electric field becomes zero is:

What is the electric field at the center of a semi-circular ring of radius $R$ having a linear charge density $\lambda$? $\left( k = \frac{1}{4\pi \varepsilon_0} \right)$

$A$ wire of length $L$ has a charge $Q$ distributed uniformly along its length. The wire is bent in the shape of a semicircle. The magnitude of the electric field at the centre of curvature of the semicircle is

$A$ point charge of $0.009 \ \mu C$ is placed at the origin. Calculate the electric field intensity due to this point charge at the point $(\sqrt{2}, \sqrt{7}, 0)$.

$A$ positive charge $q$ is placed in a spherical cavity made in a positively charged sphere. The centres of the sphere and the cavity are displaced by a small distance $\vec{l}$. The force on charge $q$ is: