Tag: science & technology

The Zeroth law of thermodynamics states that if two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other. This establishes thermal equilibrium as a transitive relation, which is fundamental to temperature measurement.

The Second Law of Thermodynamics states that in any cyclic process, heat cannot be completely converted into work - some energy is always lost as waste heat. The Zeroth Law deals with thermal equilibrium, First Law with energy conservation, and Third Law with absolute zero.

The Third Law of Thermodynamics states that it's impossible to reach absolute zero (0 Kelvin) in a finite number of operations. As temperature approaches absolute zero, the entropy change approaches zero, making complete cooling unachievable.

Newton's Third Law states that for every action, there is an equal and opposite reaction. This is the law that describes action-reaction pairs of forces.

The First Law of Thermodynamics is the law of conservation of energy - energy can neither be created nor destroyed, only transformed from one form to another.

Enthalpy is measured in Joules (J) in the SI system. Options like kg/hr (mass flow rate), Newtons (force), and N/m² (pressure) are not units of enthalpy.

An isentropic process is a reversible adiabatic process in which entropy remains constant throughout. 'Iso' means constant and 'tropic' refers to entropy.

An isobaric process is a thermodynamic process where pressure remains constant throughout. 'Iso' means constant and 'baric' refers to pressure (bar is a pressure unit).

An adiabatic process is one in which no heat is transferred to or from the system (Q=0). The system is thermally isolated from its surroundings, so heat transfer is zero.

In an isentropic (constant entropy) expansion process, the pressure decreases as the volume increases. This is an adiabatic reversible process where no heat is exchanged with the surroundings.