There exists a uniform electric field $E=4 \times 10^5 \,Vm ^{-1}$ directed along negative $x$-axis such that electric potential at origin is zero. Acharge of $-200 \,\mu C$ is placed at origin, and a charge of $+200 \,\mu C$ is placed at $(3 \,m , 0)$. The electrostatic potential energy of the system is ...........$J$

Charge $q_{2}$ is at the centre of a circular path with radius $r$. Work done in carrying charge $q_{1}$, once around this equipotential path, would be

An electron with an initial speed of $4.0 \times 10^6 \,ms ^{-1}$ is brought to rest by an electric field. The mass and charge of an electron are $9 \times 10^{-31} \,kg$ and $1.6 \times 10^{-19} \,C$, respectively. Identify the correct statement.

In a region of space, suppose there exists a uniform electric field $\vec{E}=10 i\left(\frac{ v }{ m }\right)$. If a positive charge moves with a velocity $\vec{v}=-2 \hat{j}$, its potential energy

Two electrons are moving towards each other, each with a velocity of $10^6 \,m / s$. What will be closest distance of approach between them is ......... $m$

A positively charged ring is in $y-z$ plane with its centre at origin. A positive test charge $q_0$, held at origin is released along $x$-axis, then its speed