In the given circuit,find the value of resistance $R$ if the current flowing through the circuit is $1 \, A$.

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 circuits shown below, the readings of the voltmeters and the ammeters will be:

The equivalent resistance of the infinite network given below is:

$A$ wire when connected to $220\,V$ mains supply has power dissipation $P_1$. Now the wire is cut into two equal pieces which are connected in parallel to the same supply. Power dissipation in this case is $P_2$. Then $P_2:P_1$ is

In the adjoining circuit,the $e.m.f.$ of the cell is $2 \, V$ and the internal resistance is negligible. The resistance of the voltmeter is $80 \, \Omega$. The reading of the voltmeter will be ............. $V$.