$A$ proton is accelerated through $50,000 \, V$. Its energy will increase by

Four electric charges $+q, +q, -q$ and $-q$ are placed in order at the corners of a square of side $2L$. The electric potential at point $P$,which is midway between the two positive charges,is:

Electric potential at a point distant $0.5 \,m$ from a spherical conductor of radius $0.2 \,m$ charged to $+1 \,nC$ is

Which of the following graphs correctly shows how the electrostatic potential $V$ varies with distance $r$ from a point charge?

Four point charges are placed at the vertices of a square of side $2.8 \,m$ as shown in the figure. Find the electric potential at the centre of the square. (in $\,V$)

Three concentric spherical shells have radii $a, b$ and $c$ $(a < b < c)$ and have surface charge densities $\sigma, -\sigma$ and $\sigma$ respectively. If $V_A, V_B$ and $V_C$ denote the potentials of the three shells,then,for $c = a + b$,we have