Three point charges of magnitude $5 \mu C , 0.16 \mu C$ and $0.3 \mu C$ are located at the vertices $A , B , C$ of a right angled triangle whose sides are $AB =3\,cm$, $BC =3 \sqrt{2}\,cm$ and $CA =3\,cm$ and point $A$ is the right angle corner. Charge at point $A$ experiences

$N$ of electrostatic force due to the other two charges.

Consider a system of three charges $\frac{q}{3},\frac{q}{3}$ and $\frac{-2q}{3}$ placed at points $A,B$ and $C$, respectively, as shown in the figure. Take $O$ to be the centre of the circle of radius $R$ and angle $CAB = 60^o$

When ${10^{14}}$ electrons are removed from a neutral metal sphere, the charge on the sphere becomes……$\mu C$

Two identical charges $+Q $ are kept fixed some distance apart. A small particle $P $ with charge $q$ is placed midway between them. If $P$  is given a small displacement $\Delta$ , it will undergo simple harmonic motion if

Two charges, each equal to $q$, are kept at $x = -a$ and $x = a$ on the $x-$axis. A particle of mass $m$ and charge $q_0=\frac{q}{2}$ is placed at the origin. If charge $q_0$ is given a small displacement $(y < < a)$ along the $y-$axis, the net force acting on the particle is proportional to