Question

From what I read about the Carnot Cycle, there are 4 major steps involved, viz. Isothermal Expansion, Adiabatic expansion, Isothermal compression and Adiabatic compression. During the Isothermal expansion phase, the piston-cylinder setup is at a temperature T₁ and a heat reservoir is at the same temperature T₁. When they are brought in contact, heat flows from the hot reservoir to the cylinder and since the temperature of the cylinder remains the same, the cylinder does work (Expands) isothermally. If heat always flows from a hotter body to a colder body, why did heat flow from the hot reservoir to the cylinder given that they are the same temperature?

Answer 1

In the Carnot Cycle, heat flows from the hot reservoir to the cylinder even though they are at the same temperature because the gas cools during expansion, allowing heat transfer. The expansion of the gas causes a decrease in temperature, which allows heat to enter the system from the hot reservoir.

Step-by-step explanation:

In the case of the Carnot Cycle, heat flows from the hot reservoir to the cylinder even though they are at the same temperature because the expansion of the gas cools the gas to a lower temperature. As weights are removed from the piston, the piston accelerates, causing the volume to increase. The decrease in volume results in a decrease in temperature, allowing heat to transfer from the hot reservoir to the gas to maintain the same temperature.