$A$ 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:

Temperature of cold junction in a thermocouple is $10^{\circ} C$ and neutral temperature is $270^{\circ} C$, then the temperature of inversion is (in $^{\circ} C$)

In a copper voltameter,the mass deposited in $6 \text{ min}$ is $m \text{ g}$. If the current-time graph for the voltameter is as shown in the figure,then the $E.C.E.$ of the copper is:

$A$ silver and a copper voltameter are connected in parallel across a $6\,V$ battery of negligible resistance. In half an hour,$1\,g$ of copper and $2\,g$ of silver are deposited. The rate at which energy is supplied by the battery will approximately be ............... $W$ (Given $E.C.E.$ of copper $= 3.294 \times 10^{-4}\,g/C$ and $E.C.E.$ of silver $= 1.118 \times 10^{-3}\,g/C$).

The thermo emf of a hypothetical thermocouple varies with the temperature $\theta$ of the hot junction as $E = a\theta + b\theta^2$ in volts,where the ratio $a/b$ is $700^{\circ}C$. If the cold junction is kept at $0^{\circ}C$,then the neutral temperature is:

The bulb which glows with maximum intensity in the given circuit is