A balloon rubbed with wool and a refill rubbed with polythene attract each other when brought nearby because both the balloon and refill becomes positively charged.

As shown in the figure, two particles, each of mass $\text{'}m\text{'}$ tied at the ends of a light string of length $2a$ are kept on a frictionless horizontal surface. When the mid point $\left(P\right)$ of the string is pulled vertically upwards with a small but constant force $F,$ the particles move towards each other on the surface. Magnitude of acceleration of each particle, when the separation between them becomes $2x$ is

Which of the following four figures correctly show the forces that three charged particles exert on each other?
$\left(\mathrm{i}\right)$

$\left(\mathrm{ii}\right)$
$\left(\mathrm{iii}\right)$

$\left(\mathrm{iv}\right)$

The figure represents a crystal unit of cesium chloride,$\mathrm{CsCl}$. The cesium atoms, represented by open circles are situated at the corners of a cube of side $0.40 \mathrm{nm}$, whereas  $\mathrm{Cl}$ atom is situated at the centre of the cube. The $\mathrm{Cs}$atoms are deficient in one electron while the atom carries an excess electron.
Suppose that the $\mathrm{Cs}$ atom at the corner A is missing. What is the net force on the $\mathrm{Cl}$atom due to seven remaining $\mathrm{Cs}$atoms?

Figure shows tracks of three charged particles in a uniform electrostatic field. Give the signs of the three charges. Which particle has the highest charge to mass ratio?

Two pith balls each with mass $m$ are suspended from insulating threads. When the pith balls are given equal positive charge $Q$, they hang in equilibrium as shown. We now increase the charge on the left pith ball from $Q$ to $2Q$ while leaving its mass essentially unchanged. Which of the following diagrams best represents the new equilibrium configuration?

The figure presents a crystal unit of cesium chloride,$\mathrm{CsCl}$. The cesium atoms, represented by open circles are situated at the comers of a cube of side $0.40 \mathrm{nm}$, whereas $\mathrm{Cl}$ atom is situated at the center of the cube. The $\mathrm{Cs}$atoms are deficient in one electron while the $\mathrm{Cl}$ atom carries an excess electron. What is the net electric field on the $\mathrm{Cl}$ atom due to eight $\mathrm{Cs}$ atoms ?

Two positive charges $q_2$ and $q_3$ fixed along the $y-\mathrm{axis}$, exert a net electric force In the $+x$ direction on a charge $q_1$, fixed along the $x-\mathrm{axis}$ as shown. If a positive charge $Q$ Is added at$\left(x, 0\right)$, the force on $q_1$,

Write the quadrants in which the following points lie:

$\left(-4,7\right)$