A 120 W electric soldering iron is designed for a voltage of 220 volts, determine the current

| May 11, 2021 | education

A 120 W electric soldering iron is designed for a voltage of 220 volts, determine the current strength in the soldering iron winding and its resistance.

The power of an electric soldering iron is calculated by the formula:
P = U * I, where P is the power of the electric soldering iron (P = 120 W), U is the voltage in the network (U = 220 V), I is the current in the winding of the soldering iron.
Let us express and calculate the value of the current in the soldering iron winding:
I = P / U = 120/220 ≈ 0.55 A.
According to Ohm’s Law:
I = U / R, where R is the resistance of the soldering iron winding.
Let us express and calculate the resistance of the soldering iron winding:
R = U / I = 220 / 0.55 = 400 ohms.
Answer: The current strength is 0.55 A, the resistance of the soldering iron winding is 400 Ohm.



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