If an electron moves from rest from a point at which potential is $50\, volt$ to another point at which potential is $70\, volt$, then its kinetic energy in the final state will be

For an infinite line of charge having charge density $\lambda $ lying along $x-$ axis, the work required in moving charge $q$ from $C$ to $A$ along arc $CA$ is :-

A uniformly charged thin spherical shell of radius $\mathrm{R}$ carries uniform surface charge density of $\sigma$ per unit area. It is made of two hemispherical shells, held together by pressing them with force $\mathrm{F}$ (see figure). $\mathrm{F}$ is proportional to

Explain electrostatic potential energy difference and give the noteworthy comments on it.

A problem of practical interest is to make a beam of electrons turn at $90^o$ corner. This can be done with the electric field present between the parallel plates as shown in the figure. An electron with kinetic energy $8.0 × 10^{-17}\ J$ enters through a small hole in the bottom plate. The strength of electric field that is needed if the electron is to emerge from an exit hole $1.0\ cm$ away from the entrance hole, traveling at right angles to its original direction is $y × 10^5\ N/C$ . The value of $y$ is

Potential atapoint $A$ is $3 $ $ volt$ and atapoint $B$ is $7$ $volt$,an electron is moving towards $A$ from $B.$