What is an isobaric process?

An isobaric process is characterized by a constant pressure throughout the entire process. In this scenario, when a gas expands or contracts, its pressure remains unchanged, allowing for the exchange of heat and work while maintaining the same pressure level. This concept is important in thermodynamics and is often associated with various processes, such as heating a gas in a closed system where the volume can change but the pressure does not.

In practical applications, isobaric processes can be observed in various systems, such as a piston-cylinder arrangement where gas inside the cylinder expands against a constant external atmospheric pressure. During this process, the gas can absorb heat from its surroundings, leading to an increase in its volume, but because the pressure remains constant, the relationship governed by the ideal gas law can be easily applied to analyze the changes in temperature, volume, and internal energy.

The other choices refer to different types of thermodynamic processes. For instance, expansion at constant temperature describes an isothermal process, while expansion at constant volume is an isochoric process. Variable pressure refers to processes that do not maintain constant pressure or volume and involve changing pressure conditions, which does not apply to the definition of an isobaric process.