$A$ spherical drop of mercury having a potential of $2.5\, V$ is obtained as a result of merging $125$ droplets. The potential of constituent droplets would be........$V$

$A$ particle of charge $Q$ and mass $M$ moves in a circular path of radius $R$ in a uniform magnetic field of magnitude $B$. The same particle now moves with the same speed in a circular path of same radius $R$ in the space between the cylindrical electrodes of a cylindrical capacitor. The radius of the inner electrode is $R/2$ while that of the outer electrode is $3R/2$. Then the potential difference between the capacitor electrodes must be

$A$ parallel plate capacitor,after being charged,is kept connected to a battery,and the plates are pulled apart with the help of insulating handles. Which of the following quantities will decrease?

In $Millikan's$ oil drop experiment,a charge $Q$ is held stationary between two plates under a potential difference of $2400\, V$. If a second drop with half the radius is to be held stationary using a potential difference of $600\, V$,then the charge on the second drop is:

When we touch the terminals of a high voltage capacitor,even after the power supply has been disconnected,the capacitor has a tendency to:

The potential differences that must be applied across the parallel and series combination of $3$ identical capacitors are such that the energy stored in them becomes the same. The ratio of the potential difference in the parallel combination to the series combination is: