#isobaric expansion

Work Heat Distinction and Energy Transfer Modes

In an isobaric process, 1.1 moles of an ideal gas expand from 7 L to 14 L at 390 K . What is the work done by the gas? (

**Energy transfer** first law ΔU = Q - W, W includes P-V work, shaft work, electrical work, Q includes conduction Fourier law, convection, radiation Stefan-Boltzmann, distinction important because work is controllable, heat spontaneous from hot to cold, entropy associated with heat not work, explaining why heat engine efficiency

Ref: NCERT > Physics Book > Thermodynamics > Work Heat Distinction and Energy Transfer Modes

View Details

Second Law Heat Engines and Kelvin-Planck

In an isobaric process, 0.9 moles of an ideal gas expand from 4 L to 10 L at 340 K . What is the work done by the gas? (

**Second law Kelvin-Planck statement** no process possible whose sole result is absorption of heat from reservoir and complete conversion to work, heat engine must have at least two reservoirs hot and cold, efficiency η = W/Q_h =1 - Q_c/Q_h

Ref: NCERT > Physics Book > Thermodynamics > Second Law Heat Engines and Kelvin-Planck

View Details

Second Law Heat Engines and Kelvin-Planck

In an isobaric process, 1.4 moles of an ideal gas expand from 5 L to 11 L at 370 K . What is the work done by the gas? (

**Heat engine** absorbs Q_h from hot reservoir T_h, does work W, rejects Q_c to cold T_c, efficiency η = W/Q_h =1 - Q_c/Q_h, second law limits η

Ref: NCERT > Physics Book > Thermodynamics > Second Law Heat Engines and Kelvin-Planck

View Details

Adiabatic Processes and Gamma Determination

In an isobaric process, 0.8 moles of gas expand from 330 K to 410 K . What is the heat supplied if C_p = 29.1 J mol⁻¹ K⁻

**Adiabatic work** W = ∫ P dV = (P₁V₁ - P₂V₂)/(γ-1), for expansion V₂>V₁ P₂

Ref: NCERT > Physics Book > Thermodynamics > Adiabatic Processes and Gamma Determination

View Details