$n$ identical condensers are joined in parallel and are charged to potential $V$. Now they are separated and joined in series. Then the total energy and potential difference of the combination will be
Energy and potential difference remain same
Energy remains same and potential difference is $nV$
Energy increases $n$ times and potential difference is $nV$
Energy increases $n$ times and potential difference remains same
What is energy density ? Writes its formula.
Two small spheres each carrying a charge $q$ are placed $r$ metre apart. If one of the spheres is taken around the other one in a circular path of radius $r$, the work done will be equal to
Two insulated metallic spheres of $3\,\mu F$ and $5\,\mu F$ capacitances are charged to $300\, V$ and $500\, V$ respectively. The energy loss, when they are connected by a wire is
Two capacitors each of $1\,\mu F$ capacitance are connected in parallel and are then charged by $200\;volts$ $d.c.$ supply. The total energy of their charges (in $joules$) is
A $2\,\mu F$ capacitor is charged to $100$ $volt$ and then its plates are connected by a conducting wire. The heat produced is........$J$