DC Circuits Questions

In a circuit, the current through a $4\Omega$ resistor is $1\text{A}$ when the points $P$ and $M$ are connected to a d.c. voltage source. The potential difference between the points $M$ and $N$ is:

A current of $3\text{A}$ flows through the $2\Omega$ resistor shown in the circuit. The power dissipated in the $5\Omega$ resistor is:

Consider an electric circuit consisting of two batteries with emfs ${ϵ}_1,{ϵ}_2$ and internal resistances $r_1,r_2$ connected in parallel with an external resistance $R$. If $i_1$ and $i_2$ are currents through the respective branches, which of the following Kirchhoff equations is correct?