Get Answers to all your Questions

header-bg qa

An ideal gas undergoes a quasi intatic, reversible process in which ito molar heat capacity C remain constant. If during this process the relation of pressure P and volume V is given ly p^{V^N}= constant, then N in given dy (here C_p and  C_v are molar specific heat et constant pressure ad constant volume, respectively)

Option: 1

N=\frac{c_P}{c_V}


Option: 2

N=\frac{c-c_p}{c-c_v}


Option: 3

N=\frac{C_p{-c}}{c-C_v}


Option: 4

N=\frac{C-C_v}{C-C_p}


Answers (1)

best_answer

Here, \left.P V^N=K \text { (Constant }\right)

For 1mol of ideal gas, P^V=R T

\text { Dividing (1) } by\text { (2) We get, } V^N-1_T=\frac{K}{R}

\therefore\left(\frac{d V}{d T}\right)=\frac{V}{(N-1)^T}=\frac{V}{(1-N)^T}

According to the first law of thermodynamics,

\begin{aligned} d Q & =C_V d T+p^{d V} \\ \therefore \frac{d Q}{d T} & =C_V+p\left(\frac{dV}{d T}\right)=C_V+\frac{p^V}{(1-N) T}=C_V+\frac{R}{1-N} \end{aligned}

Hence, thermal capacity C=C_v+\frac{R}{1-N} \text { or, } 1-N=\frac{{R}}{C} C_v

\begin{aligned} &\text { or, } N=1-\frac{R}{c-c_v}=\frac{c-(c_v+R)}{c-c_v}=\frac{c-c_p}{C-c_v}\\ &\left[\because C_p-c_V=R\right] \end{aligned}

Posted by

Anam Khan

View full answer