Two conductors with a resistance of 20 ohms and 30 ohms are connected in series and connected to a current source.

Two conductors with a resistance of 20 ohms and 30 ohms are connected in series and connected to a current source. In the first, 60 J of heat was released. How much heat was released in the second conductor during the same time?

R1 = 20 ohms.

R2 = 30 ohms.

Q1 = 60 J.

Q2 -?

The amount of thermal energy Q, which is released in a conductor with a current, is determined by the Joule-Lenz law: Q = I2 * R * t, where I is the current in the conductor, R is the resistance of the conductor, t is the time of current passage.

Q1 = I1 ^ 2 * R1 * t.

Q2 = I2 ^ 2 * R2 * t.

With parallel connection of conductors, the current in the common circuit I and in each resistance are the same and equal to each other: I = I1 = I2.

I1 ^ 2 * t = Q1 / R1.

The amount of thermal energy that is released in the second resistance will be expressed by the formula: Q2 = R2 * Q1 / R1.

Q2 = 30 Ohm * 60 J / 20 Ohm = 90 J.

Answer: Q2 = 90 J of thermal energy will be released in the second conductor.