Define isobaric process. Derive an expression for work done in such process.

Explanation

The process during which the pressure of system remains constant is known as isobaric process. Suppose, according to P-V graph the pressure remain constant from state `(P,V_1)` to `(P,V_2)`

`therefore` The work done by gas at constant pressure ,
`W=PDeltaV`
`=P[V_2-V_1]`
`=PV_2-PV_1`
but from the equation of an ideal gas,
`PV_1=muRT_1` and `PV_2=muRT_2`
`therefore W=muR (T_2-T_1)`
Here internal energy changes with temperature.
Some of absorbed heat is utilised for increasing internal energy and rest of energy utilised for work done.
The change in temperature for given amount heat can be determine by the formula of the specific heat at constant pressure,
`therefore C_P=(DeltaQ)/(muDeltaT)` from this `DeltaT=(DeltaQ)/C_P` (`mu` is constant)