Two identical conducting spheres $A$ and $B,$ carry equal charge. They are separated by a distance much larger than their diameter, and the force between them is $F$ . A third identical conducting sphere, $C,$ is uncharged. Sphere $C$ is first touched to $A,$ then to $B,$ and then removed. As a result, the force between $A$ and $B$ would be equal to
$\frac{{3F}}{4}$
$\frac{{F}}{2}$
$F$
$\frac{{3F}}{8}$
Two charges ${q_1}$ and ${q_2}$ are placed in vacuum at a distance $d$ and the force acting between them is $F$. If a medium of dielectric constant $4$ is introduced around them, the force now will be
Consider the charges $q, q$, and $-q$ placed at the vertices of an equilateral triangle, as shown in Figure. What is the force on each charge?
Assertion : Consider two identical charges placed distance $2d$ apart, along $x-$ axis. The equilibrium of a positive test charge placed at the point $O$ midway between them is stable for displacements along the $x-$ axis.
Reason: Force on test charge is zero
The ratio of gravitational force and electrostatic repulsive force between two electrons is approximately (gravitational constant $=6.7 \times 10^{-11} \,Nm ^2 / kg ^2$, mass of an electron $=9.1 \times 10^{-31} \,kg$, charge on an electron $=1.6 \times 10^{-19} C$ )
Two point charges placed at a certain distance $r$ in air exert a force $F$ on each other. Then the distance $r'$ at which these charges will exert the same force in a medium of dielectric constant $k$ is given by