A point charge $Q$ is placed in uniform electric field $\vec E = E_1 \hat i + E_2\hat j$ at position $(a, b)$. Find work done in moving it to position $(c, d)$
Zero
$\{E_1(c -a) + E_2(d-b)\}Q$
$\{E_1\, ac + E_2\, bd\}Q$
$\{E_1c + E_2d\}Q$
Derive the formula for the electric potential energy of system of two charges.
A point charge $q$ is surrounded by eight identical charges at distance $r$ as shown in figure. How much work is done by the forces of electrostatic repulsion when the point charge at the centre is removed to infinity?
A proton of mass $m$ and charge $e$ is projected from a very large distance towards an $\alpha$-particle with velocity $v$. Initially $\alpha$-particle is at rest, but it is free to move. If gravity is neglected, then the minimum separation along the straight line of their motion will be
A point charge $2 \times 10^{-2}\,C$ is moved from $P$ to $S$ in a uniform electric field of $30\,NC ^{-1}$ directed along positive $x$-axis. If coordinates of $P$ and $S$ are $(1,2$, $0) m$ and $(0,0,0) m$ respectively, the work done by electric field will be $.........\,mJ$
An alpha particle is accelerated through a potential difference of ${10^6}\,volt$. Its kinetic energy will be......$MeV$