need step$-$by$-$step calculation......Consider a vapour compression refrigeration system with $\backslash (\backslash$mathrm$\{$R$\}-134\backslash$mathrm$\{$a$\}\backslash )$ as medium is operating steadily. The refrigerant enters the compressor at $2\mathrm{.}8$ bar and $\backslash (5^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ and leave at $12$ bar and $70\backslash (\{\}^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ).$ The refrigerant is cooled in the condenser to $\backslash (34^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ and $11\mathrm{.}5$ bar and is throttled to $3$ bar. Neglecting any heat transfer and pressure drops in the connecting lines between the components. Solve the following questions.

a$)$ Determine the enthalpy for the four main processes of the cycle.

$(4$ marks$)$

b$)$ Sketch the T$-$s diagram of the cycle.

c$)$ Determine the energy interaction for four main components of the cycle.

d$)$ Determine the coefficient of performance $($COP$)$ of the cycle.

e$)$ Determine the isentropic efficiency of the compressor.

f$)$ Discuss the effect on the system if the condenser fan has underperformed.