For a thermocouple,the inversion temperature is $600^{\circ} C$ and the neutral temperature is $320^{\circ} C$. Find the temperature of the cold junction (in $^{\circ} C$)?

Answer the following questions:
$(a)$ $A$ steady current flows in a metallic conductor of non-uniform cross-section. Which of these quantities is constant along the conductor: current, current density, electric field, drift speed?
$(b)$ Is Ohm's law universally applicable for all conducting elements? If not, give examples of elements which do not obey Ohm's law.
$(c)$ $A$ low voltage supply from which one needs high currents must have very low internal resistance. Why?
$(d)$ $A$ high tension $(HT)$ supply of, say, $6 \ kV$ must have a very large internal resistance. Why?

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:

Which of the following circuits follows Ohm's law?

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.

One junction of a thermocouple is kept at a constant temperature $T_r$ and the other junction is kept at a temperature $T$. If the thermo-emf is given by $E = K(T - T_r) [T_0 - \frac{1}{2}(T + T_r)]$,what is the thermoelectric power at $T = \frac{1}{2}T_0$?