Zeroth law of thermodynamics|First law of thermodynamics|gtu|gate material|Thermodynamics laws

Understanding the Zeroth and First Laws of Thermodynamics

Zeroth Law of Thermodynamics

• The zeroth law states that if two bodies, A and B, are in thermal equilibrium with a third body, C, then A and B are also in thermal equilibrium with each other.

• Thermal equilibrium implies that both bodies A and B have the same temperature when in contact with body C. This is crucial for temperature measurement principles.

• The term "zeroth law" was introduced after the first law of thermodynamics was established, hence its name. It emphasizes foundational concepts in thermodynamic theory.

First Law of Thermodynamics

• The first law asserts that energy cannot be created or destroyed; it can only be converted from one form to another. This principle is known as the law of conservation of energy.

• When a system undergoes a change of state, both heat transfer (Q) and work transfer (W) occur, leading to net energy storage within the system represented by ΔE = Q - W.

• In a closed system where mass remains constant, changes in potential energy (ΔPE) and kinetic energy (ΔKE) are zero due to no elevation or movement; thus ΔE simplifies to ΔU (change in internal energy).