In the circuit shown,the energy stored in the capacitor is $n\,\mu J$. The value of $n$ is ..............

The diagram shows a circuit used in an experiment to determine the $emf$ $(E)$ and internal resistance $(r)$ of the cell $C$. $A$ graph was plotted of the potential difference $V$ between the terminals of the cell against the current $I$,which was varied by adjusting the rheostat. The graph is shown on the right; $x$ and $y$ are the intercepts of the graph with the axes as shown. What is the internal resistance of the cell?

In the circuit shown below,the reading of the voltmeter $V$ is ........... (in $, V$)

In the circuit shown,the resistance $r$ is a variable resistance. If for $r = fR$,the heat generation in $r$ is maximum,then the value of $f$ is:

An electric iron draws $5\, A$,a $TV$ set draws $3\, A$,and a refrigerator draws $2\, A$ from a $220\, V$ main line. The three appliances are connected in parallel. If all three are operating at the same time,the fuse used should be of ............. $A$. (in $, A$)

For what value of resistance $R$ in the given circuit will the galvanometer reading be zero (in $Omega$)? The internal resistance of both batteries is negligible.