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 $^{\circ} C$)

Consider the circuit given here. The potential difference $V_{BC}$ between the points $B$ and $C$ is (in $V$)

The battery shown in the figure has an $e.m.f.$ $E$ and internal resistance $r$. The current in the circuit can be varied by sliding the contact $J$. If at any instant the current flowing through the circuit is $I$,the potential difference between the terminals of the cell is $V$,and the thermal power generated in the cell is equal to $\eta$ fraction of the total electrical power generated in it,then which of the following graphs is correct?

The electrochemical equivalent of a substance is numerically equal to the mass of the substance deposited if a current $I$ flows through the electrolyte for $0.25\,s$. The value of $I$ is ................ $A$.

The ends of an element of zinc wire are kept at a small temperature difference $\Delta T$ and a small current $I$ is passed through the wire. Then, the heat developed per unit time

In the circuit shown here,the readings of the ammeter and voltmeter are