The temperature of the cold junction of a thermocouple is $0\,^{\circ}C$ and the temperature of the hot junction is $T\,^{\circ}C$. The e.m.f. is $E = 16T - 0.04T^2 \, \mu\text{V}$. The temperature of inversion is ................ $^{\circ}C$.

$A$ cell of emf $E$ is connected to a resistance $R_{1}$ for time $t$ and the amount of heat generated in it is $H$. If the resistance $R_{1}$ is replaced by another resistance $R_{2}$ and is connected to the cell for the same time $t$, the amount of heat generated in $R_{2}$ is $4H$. Then the internal resistance $r$ of the cell is:

$A$ uniform metallic wire of length $L$ is mounted in two configurations. In configuration $1$ (triangle),it is an equilateral triangle and a voltage $V$ is applied to corners $A$ and $B$. In configuration $2$ (circle),it is bent in the form of a circle and the potential $V$ is applied at diametrically opposite points $P$ and $Q$. The ratio of the power dissipated in configuration $1$ to configuration $2$ is

Consider the following statements $A$ and $B$ and identify the correct answer given below.
$A$. Peltier coefficient is numerically equal to the potential difference across the junctions of the thermocouple through which current is flowing.
$B$. According to Thomson, energy is neither absorbed nor evolved at the junction of a thermocouple but is absorbed or evolved only along the lengths of both the conductors.

$A$ battery consists of a variable number $n$ of identical cells,each having electromotive force $E$ and internal resistance $r$,connected in series. The terminals of the battery are short-circuited,and the current $I$ is measured. Which one of the graphs below shows the relationship between $I$ and $n$?

The figure shows a network of four resistances and three batteries. The electrical power dissipated as heat in the circuit is .............. $W$.