🔥 Thermodynamics

1. Thermal Equilibrium & Zeroth Law

Two systems are in thermal equilibrium if they have the same temperature.

🔥 Zeroth Law of Thermodynamics

If system A and B are in thermal equilibrium with system C separately, then A and B are in thermal equilibrium with each other. (This law introduces the concept of Temperature).

2. First Law of Thermodynamics

It is essentially the law of conservation of energy applied to heat systems.

ΔQ = ΔU + ΔW Heat supplied (ΔQ) = Change in Internal Energy (ΔU) + Work done by the system (ΔW)

3. Thermodynamic Processes

Isothermal: Temperature is constant (ΔT = 0). PV = constant. Work = nRT ln(V₂/V₁).
Adiabatic: No heat exchange (ΔQ = 0). PV^γ = constant.
Isochoric: Volume is constant (ΔV = 0). Work done = 0.
Isobaric: Pressure is constant (ΔP = 0). Work = P(V₂ - V₁).

4. Specific Heat of Gases

Gases have two principal specific heats: Cp (at constant pressure) and Cv (at constant volume).

Mayer's Formula: Cp - Cv = R

5. Second Law of Thermodynamics

Heat cannot flow itself from a colder body to a hotter body. Perfect efficiency is impossible.

Carnot Engine

A theoretical ideal heat engine with maximum possible efficiency between two temperatures. Efficiency (η) = 1 - (T₂/T₁).