Consider the following statements
1. Availability is the maximum theoretical work obtainable.
2. Clapeyron’s equation for dry saturated steam is given by $(V_{g}-V_{f}) = \frac{dT_{g}}{dP}(\frac{h_{g}-h_{f}}{T_{g}})$
3. A gas can have any temperature at a given pressure unlike a vapour which has a fixed temperature at a given pressure.
4. Joule Thomson coefficient is expressed as $\mu = (\partial s/\partial p)_{h}$
Which of these statements are correct?
(a) 1,2 and 3 (b) 1,3 and 4
(c) 2 and 3 (d) 1,2 and 4