Two identical conducting spheres carrying different charges attract each other with a force $F$ when placed in air medium at a distance $'d'$ apart. The spheres are brought into contact and then taken to their original positions. Now the two spheres repel each other with a force whose magnitude is equal to that of the the initial attractive force. The ratio between initial charges on the spheres is
$ - \left( {3 + \sqrt 8 } \right)$ only
$ - 3 + \sqrt 8 $
$ - \left( {3 + \sqrt 8 \,} \right)$ or $\left( { - 3 + \sqrt 8 } \right)$
$+\sqrt 3$
Write value of Coulombian constant $k$ in $SI$ unit.
Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle of $30^{\circ}$ with each other. When suspended in a liquid of density $0.8 \;g\, cm ^{-3}$, the angle remains the same. If density of the material of the sphere is $1.6\; g \,cm ^{-3}$, the dielectric constant of the liquid is
A charge of $4\,\mu C$ is to be divided into two. The distance between the two divided charges is constant. The magnitude of the divided charges so that the force between them is maximum, will be.
Three point charges are placed at the corners of an equilateral triangle. Assuming only electrostatic forces are acting
Two point charges $ + 3\,\mu C$ and $ + 8\,\mu C$ repel each other with a force of $40\,N$. If a charge of $ - 5\,\mu C$ is added to each of them, then the force between them will become....$N$