Question

A diatomic gas obeys the law `pV^x=` constant. For what value of x, it has negative molar specific heat?
A. (a) `xgt1.4`
B. (b) `xlt1.4`
C. (c) `1ltxlt1.4`
D. (d) 0ltxlt1

Answer 1

Correct Answer - C
`C=C_V+(R)/(1-x)`
`=5/2R+(R)/(1-x)=5/2R=(R)/(x-1)`
C is negative if
`x-1lt2/5`
`:.` `xlt1.4`
If x lies between 1 and 1.4, then also C is negative.