Two identical light conducting balls having different charges, are being suspended freely. They are pushed towards each other as shown in the given figure.

Which of the following options shows the correct position of the two balls, just after they touch each other?

Mention one difference between mass and charge.

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?
$\left(\mathrm{i}\right)$

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

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

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?