In the circuit shown,what is the potential difference $V_{PQ}$?

State and explain Kirchhoff's first law (Junction law) and Kirchhoff's second law (Loop rule).

To measure the temperature coefficient of resistivity $\alpha$ of a semiconductor,an electrical arrangement shown in the figure is prepared. The arm $BC$ is made up of the semiconductor. The experiment is being conducted at $25^{\circ} C$ and the resistance of the semiconductor arm $BC$ is $3 \ m\Omega$. Arm $BC$ is cooled at a constant rate of $2^{\circ} C / s$. If the galvanometer $G$ shows no deflection after $10 \ s$,then $\alpha$ is:

The current $I$ in the circuit shown is:

If the resistances are chosen for the circuit shown in the figure in such a way that no current flows through the battery with emf $E_1 = 2 \ V$,the voltage $V_2$ across $R_2$ and the current $I_3$ flowing through $R_3$ are respectively,

The figure shows currents in a part of an electric circuit. Then the current $I$ is: (in $A$)