What is the resistance of a soldering iron, the current strength of which is 0.3 A, if in 1 hour
| August 17, 2021 | education
What is the resistance of a soldering iron, the current strength of which is 0.3 A, if in 1 hour it emits an amount of heat equal to 324 kJ?
I = 0.3 A.
t = 1 h = 3600 s.
Q = 324 kJ = 324000 J.
R -?
The amount of thermal energy Q, which is released when an electric current passes through it, is determined by the Joule-Lenz law: Q = I ^ 2 * R * t, where I is the strength of the electric current, R is the resistance of the conductor, in our case, the soldering iron, t is the time passage of current.
The resistance of the soldering iron R is expressed by the formula: R = Q / I ^ 2 * t.
R = 324000 J / (0.3 A) ^ 2 * 3600 s = 1000 Ohm = 1 kOhm.
Answer: the soldering iron has a resistance R = 1 kOhm.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.
