A $30\,\mu F$ capacitor is charged by a constant current of $30\, mA$. If the capacitor is initially uncharged, how long does it take for the potential difference to reach $400\, V$.....$s$

The charges on two plates of a $10\,\mu f$ capacitor are $5\,\mu C$ and $15\,\mu C$ then the potential difference across the capacitor plates is........$V$

The potentials of the two plates of capacitor are $+10\,V$ and $-10\, V$. The charge on one of the plates is $40 \,C$. The capacitance of the capacitor is........$F$

Can there be a potential difference between two adjacent conductors carrying the same charge ?

Two identical thin metal plates has charge $q _{1}$ and $q _{2}$ respectively such that $q _{1}> q _{2}$. The plates were brought close to each other to form a parallel plate capacitor of capacitance $C$. The potential difference between them is.

Eight drops of mercury of equal radii possessing equal charges combine to form a big drop. Then the capacitance of bigger drop compared to each individual small drop is........$times$