JEE Main Electrostatics Practice Questions With Solutions

Two charges $q$q and $3q$3 q are separated by a distance '$r$r' in air. At a distance $x$x from charge $q$q, the resultant electric field is zero. The value of $x$x is :

A particle of charge '$-q$- q' and mass '$m$m' moves in a circle of radius '$r$r' around an infinitely long line charge of linear charge density '$+\lambda$+ \lambda'. Then time period will be given as :

(Consider $k$k as Coulomb's constant)

The electrostatic potential due to an electric dipole at a distance '$r$r' varies as :

An electric field is given by $(6\hat{i}+5\hat{j}+3\hat{k})\mathrm{N}/\mathrm{C}$\left(\right. 6 \hat{i} + 5 \hat{j} + 3 \hat{k} \left.\right) N / C. The electric flux through a surface area $30\hat{i}{\mathrm{m}}^2$30 \hat{i} \left(\textrm{ } m\right)^{2} lying in YZ-plane (in SI unit) is :

Two charges of $5Q$5 Q and $-2Q$- 2 Q are situated at the points $(3a,0)$\left(\right. 3 a , 0 \left.\right) and $(-5a,0)$\left(\right. - 5 a , 0 \left.\right) respectively. The electric flux through a sphere of radius '$4a$4 a' having center at origin is :

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Work done by electric field on moving a positive charge on an equipotential surface is always zero.

Reason (R) : Electric lines of forces are always perpendicular to equipotential surfaces.

In the light of the above statements, choose the most appropriate answer from the options given below :

An electric charge ${10}^{-6}\mu \mathrm{C}$10^{- 6} \mu C is placed at origin $(0,0)$\left(\right. 0 , 0 \left.\right)$\mathrm{m}$m of $\mathrm{X}-\mathrm{Y}$X - Y co-ordinate system. Two points $\mathrm{P}$P and $\mathrm{Q}$Q are situated at $(\sqrt{3},\sqrt{3})\mathrm{m}$\left(\right. \sqrt{3} , \sqrt{3} \left.\right) m and $(\sqrt{6},0)\mathrm{m}$\left(\right. \sqrt{6} , 0 \left.\right) m respectively. The potential difference between the points $\mathrm{P}$P and $\mathrm{Q}$Q will be :

A $10\mu \mathrm{C}$10 \textrm{ } \mu C charge is divided into two parts and placed at $1\mathrm{cm}$1 \textrm{ } cm distance so that the repulsive force between them is maximum. The charges of the two parts are:

Two charges each of magnitude $0.01\mathrm{C}$0.01 \textrm{ } C and separated by a distance of $0.4\mathrm{mm}$0.4 \textrm{ } mm constitute an electric dipole. If the dipole is placed in an uniform electric field '$\overrightarrow{E}$\overset{\rightarrow}{E}' of 10 dyne/C making ${30}^{\circ }$30^{\circ} angle with $\overrightarrow{E}$\overset{\rightarrow}{E}, the magnitude of torque acting on dipole is: