Two balls of same mass and carrying equal charge are hung from a fixed support of length $l$. At electrostatic equilibrium, assuming that angles made by each thread is small, the separation, $x$ between the balls is proportional to
$l$
$l^2$
${l^{2/3}}$
${l^{1/3}}$
Three points charges are placed at the corners of an equilateral triangle of side $L$ as shown in the figure.
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 $q_3$ ?
The electrostatic force of interaction between an uniformly charged rod having total charge $Q$ and length $L$ and a point charge $q$ as shown in figure is
Two free point charges $+q$ and $+4q$ are a distance $R$ apart. $A$ third charge is so placed that the entire system is in equilibrium. Then the third charge is :-
Two protons $A$ and $B$ are placed in space between plates of a parallel plate capacitor charged upto $V$ volts (See fig.) Forces on protons are ${F_A}$ and ${F_B}$, then