The value of electric permittivity of free space is
$9 \times {10^9}\,N{C^2}/{m^2}$
$8.85 \times {10^{ - 12}}\,N{m^2}/{C^2}sec$
$8.85 \times {10^{ - 12}}\,{C^2}/N{m^2}$
$9 \times {10^9}\,{C^2}/N{m^2}$
Two charges $q$ and $-3q$ are placed fixed on $x-axis$ separated by distance $'d'$. Where should a third charge $2q$ be placed such that it will not experience any force ?
Explain the superposition principle for static electric forces and write its general equation.
There are two charges $+1$ microcoulombs and $+5$ microcoulombs. The ratio of the forces acting on them will be
A charge $q$ is placed at the centre of the line joining two equal charges $Q$. The system of the three charges will be in equilibrium, if $q$ is equal to
The law, governing the force between electric charges is known as