Which alloy is used to make the heating element (resistance wire) in an electric iron?

What is the unit of $Watt-second$?

What are the factors on which the resistance of a conductor depends?

If $2 \times 10^{-3} \text{ J}$ of work is done in moving a particle carrying a charge of $10 \times 10^{-6} \text{ C}$ from infinity to a point $P$, what will be the potential at the point $P$ (in $\text{ V}$)?

The $V-I$ graphs for two wires $A$ and $B$ are shown in the figure. If we connect both the wires one by one to the same battery, which of the two will produce more heat per unit time? Give justification for your answer.

$A$ bulb gets dimmer for a moment when a geyser,connected across the same source,is switched on. Why?