When a current of $1\, A$ is passed through a conductor whose ends are maintained at a temperature difference of $1\, ^oC$,the amount of heat evolved or absorbed is called:

Antimony and bismuth are usually used in a thermocouple,because

Assertion : An electric bulb becomes dim,when the electric heater in parallel circuit is switched on.
Reason : Dimness decreases after sometime.

$A$ 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:

When a current $I$ is passed through a wire of constant resistance,it produces a potential difference $V$ across its ends. The graph drawn between $\log I$ and $\log V$ will be:

Consider the following two statements $A$ and $B$,and identify the correct choice out of the given answers:
$A$. Thermo $e.m.f.$ is minimum at the neutral temperature of a thermocouple.
$B$. When two junctions made of two different metallic wires are maintained at different temperatures,an electric current is generated in the circuit.