The distance between charges $5 \times {10^{ - 11}}\,C$ and $ - 2.7 \times {10^{ - 11}}\,C$ is $0.2\, m$. The distance at which a third charge should be placed in order that it will not experience any force along the line joining the two charges is......$m$

Three point charges $q_1, q_2, q_3$ are placed at the vertices of a triangle if force on $q_1$ and $q_2$ are $\left( {2\hat i - \hat j} \right)\,N$ and $\left( {\hat i + 3\hat j} \right)\,N$, respeactively, then what will be force on $q_3$ ?

Two identical conducting spheres $\mathrm{P}$ and $\mathrm{S}$ with charge $Q$ on each, repel each other with a force $16 \mathrm{~N}$. A third identical uncharged conducting sphere $\mathrm{R}$ is successively brought in contact with the two spheres. The new force of repulsion between $\mathrm{P}$ and $\mathrm{S}$ is :

Equal charges $q$ are placed at the four corners $A,\,B,\,C,\,D$ of a square of length $a$. The magnitude of the force on the charge at $B$ will be

Why Coulomb’s law is associated with Newton’s $3^{rd}$ law ?

Four point $+ve$ charges of same magnitude $(Q)$ are placed at four corners of a rigid square frame as shown in figure. The plane of the frame is perpendicular to $Z$ axis. If a $-ve$ point charge is placed at a distance $z$ away from the above frame $(z<< L)$ then