An electric iron has a rating of $$750\ W, 220\ V$$. Calculate the (i) current flowing through it, and (ii) its resistance when in use.
Given :
Power rating $$P = 750\ W $$
Rated voltage $$ V = 220\ V $$
$$(i)$$ We know $$ P = VI $$
$$750 = 220 \times I $$
$$ \Rightarrow $$ $$I = \dfrac{750}{220} = 3.40\ A $$
$$(ii)$$ Also, power can also be wriiten as
$$P = \dfrac{V^2}{R} $$
$$ \Rightarrow $$ $$R = \dfrac{V^2}{P} = \dfrac{220^2}{750}$$
So resistance of electric iron $$R = 64.53\ \Omega $$