$${\left( {\frac{{\partial {\text{T}}}}{{\partial {\text{P}}}}} \right)_{\text{H}}}$$  is the mathematical expression for

A. Specific heat at constant pressure (C_p)

B. Specific heat at constant volume (C_v)

C. Joule-Thompson co-efficient

D. None of these

Answer: Option C

Solution(By Examveda Team)

Joule-thomson coefficient is nothing but the slope graph between temperature and pressure which is a plot obtained experimentally under constant enthalpy conditions $${\left( {\frac{{\partial T}}{{\partial P}}} \right)_H} = \mu .$$
There is huge significance for this and is used to tell whether a fluid undergoes cooling or heating by throttling.