The electric resistance of a certain wire of iron is $R$. If its length and radius are both doubled, then

The current in the $1 \mathrm{\Omega }$ resistor shown in the circuit is,

The figure below shows currents in a part of electric circuit. The current $i$ is

Two batteries of emfs $\mathrm{4\; V}$ and $\mathrm{8\; V}$ with internal resistances $\mathrm{1 }\mathrm{\Omega }$ and $\mathrm{2 }\mathrm{\Omega }$ are connected in a circuit with a resistance of $\mathrm{9 }\mathrm{\Omega }$ as shown in figure. The current and potential difference between the points $\mathit{P}$ and $\mathit{Q}$ are,