key term - Cyclical process

Definition

A cyclical process is a series of thermodynamic steps that return a system to its initial state. In such processes, the total change in internal energy over one complete cycle is zero.

5 Must Know Facts For Your Next Test

1. In a cyclical process, the net work done by the system equals the net heat added to the system.
2. Heat engines operate on cyclical processes to convert heat energy into mechanical work.
3. The efficiency of a heat engine operating in a cyclic process is given by $\eta = \frac{W_{net}}{Q_H}$ where $W_{net}$ is the net work done and $Q_H$ is the heat absorbed from the hot reservoir.
4. According to the Second Law of Thermodynamics, no cyclic process can convert all heat into work; some energy is always lost as waste heat.
5. The Carnot cycle represents an idealized cyclical process with maximum possible efficiency.

Review Questions

Related terms

Heat Engine: A device that converts thermal energy into mechanical work using a cyclic process.

Carnot Cycle: An idealized thermodynamic cycle with maximum efficiency consisting of two isothermal and two adiabatic processes.

Second Law of Thermodynamics:

A law stating that total entropy can never decrease over time for an isolated system and that no cyclic process can convert all heat into work.