Two small spherical balls each carrying a charge $Q = 10\,\mu C$ ($10\, micro-coulomb$) are suspended by two insulating threads of equal lengths $3\, m$ each, from a point fixed in the ceiling. It is found that in equilibrium threads are separated by an angle $120^o$ between them, as shown in the figure. What is the tension in the threads (Given : $\frac{1}{{\left( {4\pi {\varepsilon _0}} \right)}} = 9 \times {10^9}\,Nm/{C^2}$)
$\left( {\frac{{0.2}}{{\sqrt 3 }}} \right)\,N$
$1.8\, N$
$\left( {\frac{{0.2}}{{\sqrt 5 }}} \right)\,N$
None of the above
A charge of $Q$ coulomb is placed on a solid piece of metal of irregular shape. The charge will distribute itself
Two particle of equal mass $m$ and charge $q$ are placed at a distance of $16\, cm$. They do not experience any force. The value of $\frac{q}{m}$ is
In the given figure two tiny conducting balls of identical mass $m$ and identical charge $q$ hang from non-conducting threads of equal length $L$. Assume that $\theta$ is so small that $\tan \theta \approx \sin \theta $, then for equilibrium $x$ is equal to
The charges on two sphere are $+7\,\mu C$ and $-5\,\mu C$ respectively. They experience a force $F$. If each of them is given and additional charge of $-2\,\mu C$, the new force of attraction will be
Positive charge $Q$ is distributed uniformly over a circular ring of radius $R$. A point particle having a mass $(m)$ and a negative charge $-q$ is placed on its axis at a distance $x$ from the centre. Assuming $x < R,$ find the time period of oscillation of the particle, if it is released from there [neglect gravity].