Isobaric Process.

When a thermodynamic system undergoes a physical change in such a way that its pressure remains constant, then the change is known as isobaric process.

In this process V and T changes but P remains constant. Hence Charle’s law is obeyed in this process.

(1) Equation of state : From ideal gas equation PV = mRT

If pressure remains constant  V µ T      or    V₁/T₁ = V₂/T₂ = constant

(2) Indicator diagram : Graph I represent isobaric expansion, graph II represent isobaric compression.

Slope of indicator diagram   dP/dV = 0

(3) Specific heat : Specific heat of gas during isobaric process

(4) Bulk modulus of elasticity :    [As ΔP = 0]

(5) Work done in isobaric process :

[As P = constant]

Therefore ΔW=P(V_f-V_i)= µR[T_f-T_i]= µRΔT

(6) FLTD in isobaric process :           and     ΔW=µRΔT 

From FLTD     ΔQ = ΔU + ΔW

Therefore

ΔQ = µC_pΔT