The cold junction of a thermocouple is at $10\,^{\circ}\text{C}$. When the temperature of the hot junction is $530\,^{\circ}\text{C}$,no thermo-emf is produced. What is the neutral temperature in $^{\circ}\text{C}$?

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?

$A$ cable consists of a copper wire of radius $9 \, mm$ having a resistance of $5 \, \Omega$. If this cable is replaced by $6$ copper wires each of radius $3 \, mm$,what will be the new resistance of the cable in $\Omega$?

When current is passed in an antimony-bismuth couple,then:

Assertion : All electric devices shown in the circuit are ideal. The reading of each of ammeter $(A)$ and voltmeter $(V)$ is zero.
Reason : An ideal voltmeter draws almost no current due to very large resistance, and hence $(V)$ and $(A)$ will read zero.

The Thomson coefficient of a conductor is $10 \mu V/K$. The two ends of the conductor are kept at $50^{\circ} C$ and $60^{\circ} C$, respectively. The amount of heat absorbed by the conductor when a charge of $10 C$ flows through it is: