The expression for thermo $e.m.f.$ in a thermocouple is given by the relation $E = 40\theta - \frac{\theta^2}{20}$,where $\theta$ is the temperature difference of two junctions. For this,the neutral temperature will be ................... $^oC$.

In the circuit shown in the figure,the $5\,\Omega$ resistance develops $20.00\,cal/s$ due to the current flowing through it. The heat developed in the $2\,\Omega$ resistance (in $cal/s$) is

$A$ cell sends a current through a resistance $R_1$ for time $t$. Now,the same cell sends a current through a resistance $R_2$ for the same time $t$. If the heat produced in both cases is the same,then the internal resistance of the cell is:

An electric kettle has two coils. When one coil is switched on,the tea gets heated in $10 \, \text{min}$. When the other coil is switched on,the same amount of tea gets heated in $40 \, \text{min}$. If both coils are connected in parallel,how long will it take to heat the same amount of tea (in $, \text{min}$)?

The value of the resistance $R$ in the figure is adjusted such that the power dissipated in the $2\,\Omega$ resistor is maximum. Then the power dissipated in the $2\,\Omega$ resistor will be ................ $W$.

$A$ galvanometer $(G)$ of $2 \ \Omega$ resistance is connected in the given circuit. The ratio of charge in $C_1$ $(4 \ \mu F)$ and $C_2$ $(6 \ \mu F)$ is: