Which of the following graphs represents the variation of power loss $P$ in the external load with external resistance $R$?

The heater of an electric kettle is made of a wire of length $L$ and diameter $d$. It takes $4$ minutes to raise the temperature of $0.5 \ kg$ of water by $40 \ K$. This heater is replaced by a new heater having two wires of the same material,each of length $L$ and diameter $2d$. The way these wires are connected is given in the options. How much time in minutes will it take to raise the temperature of the same amount of water by $40 \ K$?
$(A)$ $4$ if wires are in parallel
$(B)$ $2$ if wires are in series
$(C)$ $1$ if wires are in series
$(D)$ $0.5$ if wires are in parallel

The resistance of the filament of a lamp increases with the increase in temperature. $A$ lamp rated $100\, W, 220\, V$ is connected across a $220\, V$ power supply. If the voltage drops by $10\%$,then the power of the lamp will be:

In a thermocouple,the temperature that does not depend on the temperature of the cold junction is called

If an electric current is passed through a nerve of a man, then the man:

Statement $(I)$: The temperature coefficient of resistance for most metals in pure form is positive.
Statement $(II)$: $A$ metal wire $2 \ mm$ in diameter carries a charge of $360 \pi \ C$ in two hours. If the metal contains $5 \times 10^{22}$ free electrons $/ cm^3$, then the drift velocity of the electrons in the wire is $6.25 \times 10^{-6} \ m/s$.
Statement $(III)$: Semiconductors like pure germanium do not obey Ohm's law for all ranges of electric field values. Which of the following is correct?