An electron is moving round the nucleus of a hydrogen atom in a circular orbit of radius $r$. The coulomb force $\overrightarrow F $ between the two is (Where $K = \frac{1}{{4\pi {\varepsilon _0}}}$)
$ - K\frac{{{e^2}}}{{{r^3}}}\hat r$
$K\frac{{{e^2}}}{{{r^3}}}\vec r$
$ - K\frac{{{e^2}}}{{{r^3}}}\vec r$
$K\frac{{{e^2}}}{{{r^2}}}\hat r$
Out of gravitational, electromagnetic, Vander Waals, electrostatic and nuclear forces; which two are able to provide an attractive force between two neutrons
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 are placed at the corners of an equilateral triangle. Assuming only electrostatic forces are acting
A certain charge $Q$ is divided into two parts $q$ and $(Q-q) .$ How should the charges $Q$ and $q$ be divided so that $q$ and $(Q-q)$ placed at a certain distance apart experience maximum electrostatic repulsion?
Two point charges $ + 3\,\mu C$ and $ + 8\,\mu C$ repel each other with a force of $40\,N$. If a charge of $ - 5\,\mu C$ is added to each of them, then the force between them will become....$N$