Electric power of a circuit is the rate at which work is done in maintaining the electric current in the circuit.

$(a)$ Name the effect of electric current which is utilised in the working of an electrical fuse.
$(b)$ How is a fuse connected in a domestic circuit?

$100 \, J$ of heat is produced each second in a $4 \, \Omega$ resistance. Find the potential difference across the resistor. (in $, V$)

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

An electric bulb of resistance $480 \Omega$ is connected to a $220 \text{ V}$ main. Find the amount of electrical energy consumed in $10 \text{ seconds}$. (in $J$)

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.