Three equal charges $+q$ are placed at the three vertices of an equilateral triangle centred at the origin. They are held in equilibrium by a restoring force of magnitude $F(r)=k r$ directed towards the origin, where $k$ is a constant. What is the distance of the three charges from the origin?
$\left[\frac{1}{6 \pi \varepsilon_0} \frac{q^2}{k}\right]^{1 / 2}$
$\left[\frac{\sqrt{3}}{12 \pi \varepsilon_0} \frac{q^2}{k}\right]^{1 / 3}$
$\left[\frac{1}{6 \pi \varepsilon_{0}} \frac{q^2}{k}\right]^{2 / 3}$
$\left[\frac{\sqrt{3}}{4 \pi \varepsilon_0} \frac{q^2}{k}\right]^{2 / 3}$
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 $q_3$ ?
Three identical charged balls each of charge $2 \,C$ are suspended from a common point $P$ by silk threads of $2 \,m$ each (as shown in figure). They form an equilateral triangle of side $1 \,m$.
The ratio of net force on a charged ball to the force between any two charged balls will be ...........
For regular pentagon system shown in figure, find force on $q_0$
A thin metallic wire having cross sectional area of $10^{-4} \mathrm{~m}^2$ is used to make a ring of radius $30 \mathrm{~cm}$. A positive charge of $2 \pi \mathrm{C}$ is uniformly distributed over the ring, while another positive charge of $30$ $\mathrm{pC}$ is kept at the centre of the ring. The tension in the ring is__________ $\mathrm{N}$; provided that the ring does not get deformed (neglect the influence of gravity). (given, $\frac{1}{4 \pi \epsilon_0}=9 \times 10^9 \mathrm{SI}$ units)
Write limitation of Coulomb’s law.