In Millikan's oil drop experiment an oil drop carrying a charge $Q$ is held stationary by a potential difference $2400\,V$ between the plates. To keep a drop of half the radius stationary the potential difference had to be made $600\,V$. What is the charge on the second drop
$\frac{Q}{4}$
$\frac{Q}{2}$
$Q$
$\frac{{3Q}}{2}$
Two plates are $2\,cm$ apart, a potential difference of $10\;volt$ is applied between them, the electric field between the plates is.........$N/C$
What is potential gradient ?
Which of the following is true for the figure showing electric lines of force? ($E$ is electrical field, $V$ is potential)
The potential gradient is a
The electrostatic potential inside a charged spherical ball is given by : $V = b -ar^2$, where $r$ is the distance from the centre ; $a$ and $b$ are constants. Then, the charge density inside the ball is :