Embibe Experts Solutions for Chapter: Electrostatics, Exercise 2: BEGINNER'S BOX - 2

Two identical metal spheres carry charges of $+q$ and $-2q$ respectively. When the spheres are separated by a large distance $r$, the force between them is $F$. Now the spheres are allowed to touch and then moved back to the same separation. Find the new force of repulsion between them.

The electrostatic force of repulsion between two positive ions carrying equal charges is $4\times {10}^{-9}\mathrm{N}$, when their separation is $5$. How many electrons are missing from each?

Two identical particles each of mass $M$ and charge $Q$ are placed a certain distance apart. If they are in equilibrium under mutual gravitational and electric force then calculate the order of  $\frac{Q}{M}$ in SI units.

The force between two point charges is $100 \mathrm{N}$ in air. Calculate the force if the distance between them is increased by $50\%$.

Two neutral insulating small spheres are rubbed against each other and are then kept $4 \mathrm{m}$ apart. If they attract each other with a force of $3.6 \mathrm{N}$, then

(i) calculate the charge on each sphere, and

(ii) calculate the number of electrons transferred from one sphere to the other during rubbing.

Two equal point charges $Q=+\sqrt{2}\mu C$ are placed at each of the two opposite corners of a square and equal point charges $q$ at each of the other two corners. What must be the value of q so that the resultant force on $Q$ is zero?

In the given figure three point charges are situated at the corners of an equilateral triangle of side $10\mathrm{cm}$ . Calculate the resultant force on the charge at $B$. What is its direction?

Two positively charged particles, each of mass $1.7\times {10}^{-27} \mathrm{kg}$ and carrying a charge of  $1.6\times {10}^{-19} \mathrm{C}$ are placed at a distance $d$ apart. If each experiences a repulsive force equal to its weight, find the value of $d$.