$A$ fuse wire with radius $1\, mm$ blows at $1.5\, A$. The radius of the fuse wire of the same material to blow at $3\, A$ will be:

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:

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	$D$. $\text{Oersted} \times \text{cm}$
	$E$. $\text{Amp} \times \text{Gauss}$
	$F$. $\text{Amp}^2 \times \text{Ohm}$

The variation of current $(I)$ and voltage $(V)$ is as shown in figure $A$. The variation of power $P$ with current $I$ is best shown by which of the following graphs?

The temperature at which thermo-emf is zero is

In the given circuit,the reading of the voltmeter connected across the $400\,\Omega$ resistor is $30\,V$. If it is connected across the $300\,\Omega$ resistor,what will be its reading in $V$?