The cold junction of a thermocouple is maintained at $10\,^{\circ}C$. No thermo $e.m.f.$ is developed when the hot junction is maintained at $530\,^{\circ}C$. The neutral temperature is ................ $^{\circ}C$.

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

Consider a block of conducting material of resistivity $\rho$ shown in the figure. Current $I$ enters at $A$ and leaves from $D$. We apply the superposition principle to find the voltage $\Delta V$ developed between $B$ and $C$. The calculation is done in the following steps: $(i)$ Take current $I$ entering from $A$ and assume it to spread over a hemispherical surface in the block. $(ii)$ Calculate the field $E(r)$ at distance $r$ from $A$ by using Ohm's law $E=\rho j$,where $j$ is the current per unit area at $r$. $(iii)$ From the $r$ dependence of $E(r)$,obtain the potential $V(r)$ at $r$. $(iv)$ Repeat $(i), (ii)$ and $(iii)$ for current $I$ leaving $D$ and superpose results for $A$ and $D$. $\Delta V$ measured between $B$ and $C$ is

$A$ battery of $6$ cells,each with an $e.m.f.$ of $2\,V$ and an internal resistance of $0.5\,\Omega$,is being charged by a $220\,V$ $D.C.$ mains using an external resistor of $10\,\Omega$. What is the charging current in $A$?

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

Match List-$I$ with List-$II$ and select the correct answer using the codes given below the lists.

List-$I$	List-$II$
$I$. Joule	$A$. $\text{Henry} \times \text{Amp/sec}$
$II$. Watt	$B$. $\text{Farad} \times \text{Volt}$
$III$. Volt	$C$. $\text{Coulomb} \times \text{Volt}$
$IV$. Coulomb	$D$. $\text{Oersted} \times \text{cm}$
	$E$. $\text{Amp} \times \text{Gauss}$
	$F$. $\text{Amp}^2 \times \text{Ohm}$