A sphere of $4\, cm$ radius is suspended within a hollow sphere of $6\, cm$ radius. The inner sphere is charged to potential $3\, e.s.u.$ and the outer sphere is earthed. The charge on the inner sphere is.....$e.s.u.$
$54$
$0.25$
$30$
$36$
Write an equation for potential at a point in a uniformly charged spherical shell.
Assertion: Electron move away from a region of higher potential to a region of lower potential.
Reason: An electron has a negative charge.
Two spheres $A$ and $B$ of radius $a$ and $b$ respectively are at same electric potential. The ratio of the surface charge densities of $A$ and $B$ is
An electric field $\vec E\, = (25 \hat i + 30 \hat j)\,NC^{-1}$ exists in a region of space. If the potential at the origin is taken to be zero then the potential at $x\, = 2\, m, y\, = 2\, m$ is......$volt$
Four charges of $1\ \mu C, 2\ \mu C, 3\ \mu C,$ and $- 6\ \mu C$ are placed one at each corner of the square of side $1\,m$. The square lies in the $x-y$ plane with its centre at the origin.