A point charge $q_1$ exerts an electric force on a second point charge $q_2$. If third charge $q_3$ is brought near, the electric force of $q_1$ exerted on $q_2$
Decreases
Increases
Remains unchanged
Increases if $q_3$ is of same sign as $q_1$ and decreases if $q_3$ is of opposite sign
Two point charges $Q$ each are placed at a distance $d$ apart. A third point charge $q$ is placed at a distance $x$ from mid-point on the perpendicular bisector. The value of $x$ at which charge $q$ will experience the maximum $Coulomb's force$ is ...............
A $10\,\mu C$ charge is divided into two parts and placed at $1\,cm$ distance so that the repulsive force between them is maximum. The charges of the two parts are :
$ + 2\,C$ and $ + 6\,C$ two charges are repelling each other with a force of $12\,N$. If each charge is given $ - 2\,C$ of charge, then the value of the force will be
Write value of Coulombian constant $k$ in $SI$ unit.
Two identical conducting spheres with negligible volume have $2.1\, nC$ and $-0.1\, nC$ charges, respectively. They are brought into contact and then separated by a distance of $0.5 \,m$. The electrostatic force acting between the spheres is $.......... \, \times 10^{-9} \,N$
[Given : $4 \pi \varepsilon_{0}=\frac{1}{9 \times 10^{9}} SI$ unit]