State the factors on which the heat produced in a current-carrying conductor depends. Give one practical application of this effect.

(N/A) The heat produced $(H)$ in a current-carrying conductor is given by Joule's Law of Heating: $H = I^2Rt$.
$(i)$ The factors on which the heat produced depends are:
$(a)$ The square of the current flowing through the conductor $(I^2)$.
$(b)$ The resistance of the conductor $(R)$.
$(c)$ The time for which the current flows through the conductor $(t)$.
$(ii)$ $A$ practical application of this heating effect is the electric iron,which converts electrical energy into heat energy to press clothes.