In a $Cu-Fe$ thermocouple,what is the nature of the current flow at the temperature of inversion?

An ammeter and a voltmeter are connected in series with a cell. Their readings are $A$ and $V$ respectively. If a resistor is now connected in parallel with the voltmeter,then:

For the circuit shown in the figure:
$(A)$ The current $I$ through the battery is $7.5 \text{ mA}$.
$(B)$ The potential difference across $R_L$ is $18 \text{ V}$.
$(C)$ The ratio of powers dissipated in $R_1$ and $R_2$ is $3$.
$(D)$ If $R_1$ and $R_2$ are interchanged,the magnitude of the power dissipated in $R_L$ will decrease by a factor of $9$.

When a current passes through a wire whose different parts are maintained at different temperatures,the evolution or absorption of heat all along the length of the wire is known as:

$A$ cell of emf $E$ has an internal resistance $r$ and is connected to a rheostat. When the resistance $R$ of the rheostat is changed,which is the correct graph of the potential difference $V$ across it?

If $E$ denotes the electric field in a uniform conductor,$I$ the corresponding current through it,${v_d}$ the drift velocity of electrons,and $P$ the thermal power produced in the conductor,then which of the following graphs is incorrect?