According to the Joule-Lenz law, the amount of heat released by an electric furnace can be calculated using the formula:
Q = I ^ 2 * R * t, where Q is the released amount of heat (Q = 28.8 kJ = 28.8 * 10 ^ 3 J), I is the current strength (I = 4 A), R is the resistance of the electric furnace (Ohm), t – current passage time (t = 1 min = 60 s).
Let us express and calculate the resistance of an electric furnace:
R = Q / (I ^ 2 * t) = (28.8 * 10 ^ 3) (4 ^ 2 * 60) = 30 ohms.
Answer: The resistance of an electric oven is 30 ohms.
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.