An electric iron with a power of 400 W is switched on with a voltage of 220 V

An electric iron with a power of 400 W is switched on with a voltage of 220 V. Determine the value of the current in the heating element of the iron, resistance.

Data: P (power of the electric iron used) = 400 W; U (mains voltage) = 220 V.

1) Current in the heating element of the iron used: I = P / U = 400/220 ≈ 1.82 A.

2) Iron resistance: P = U ^ 2 / R and R = U ^ 2 / P = 220 ^ 2/400 = 121 ohms.

Answer: A current of 1.82 A flows through the heating element of the electric iron used; the resistance is 121 ohms.