In the given circuit,the potentials at points $B$,$C$,and $D$ will be:

Two sources of equal $emf$ $E$ are connected in series to an external resistance $R$. The internal resistances of the two sources are $R_1$ and $R_2$ $(R_2 > R_1)$. If the potential difference across the source having internal resistance $R_2$ is zero,then:

$A$ copper wire of radius $0.1 \text{ mm}$ and resistance $2 \text{ k}\Omega$ is connected across a power supply of $40 \text{ V}$. The number of electrons transferred per second between the supply and the wire at one end is

The resistance of an iron wire is $10\,\Omega$ and the temperature coefficient of resistivity is $5 \times 10^{-3}\,^{\circ}C^{-1}$. At $20\,^{\circ}C$,it carries $30\,mA$ of current. Keeping the potential difference between its ends constant,the temperature of the wire is raised to $120\,^{\circ}C$. The current in milliamperes that flows in the wire is:

In the given circuit,the total power loss is $10 \text{ W}$. Find the value of resistance $R$ in $\Omega$.

The smallest temperature difference that can be measured with a combination of a thermocouple of thermo $e.m.f.$ $30\,\mu V$ per degree and a galvanometer of $50\,\Omega$ resistance,capable of measuring a minimum current of $3 \times 10^{-7} \, A$ is ............... $^\circ C$.