A hollow conducting sphere of radius $R$ has a charge $( + Q)$ on its surface. What is the electric potential within the sphere at a distance $r = \frac{R}{3}$ from its centre

Assume that an electric field $\vec E = 30{x^2}\hat i$ exists in space. Then the potential difference $V_A-V_O$ where $V_O$ is the potential at the origin and $V_A$ the potential at $x = 2\ m$ is....$V$

Do free electrons travel to region of higher potential or lower potential ?

The electric potential at the surface of an atomic nucleus $(z=50)$ of radius $9 \times 10^{-13} \mathrm{~cm}$ is ________$\times 10^6 \mathrm{~V}$.

Two charges of $4\,\mu C$ each are placed at the corners $A$ and $B $ of an equilateral triangle of side length $0.2\, m $ in air. The electric potential at $C$ is $\left[ {\frac{1}{{4\pi {\varepsilon _0}}} = 9 \times {{10}^9}\,\frac{{N{\rm{ - }}{m^2}}}{{{C^2}}}} \right]$

Assertion : For a non-uniformly charged thin circular ring with net charge is zero, the electric field at any point on axis of the ring is zero.

Reason : For a non-uniformly charged thin circular ring with net charge zero, the electric potential at each point on axis of the ring is zero.