A system undergoes a state change from $$1$$ to $$2.$$ According to the second law of thermodynamics, for the process to be feasible, the entropy changes, $${S_2} - {S_1}$$ of the system

At a place where the surroundings are at $$1$$ bar $${27^ \circ }C,$$ a closed rigid thermally insulated tank contains $$2$$ $$kg$$ air at $$2$$ bar, $${27^ \circ }C,$$ This air is then churned for a while, by a paddle wheel connected to an external motor. If it is given that the irreversibility of the process is $$100$$ $$kJ,$$ find the final temperature and the increase in availability of air. Assume for air $${C_v} = 0.718\,\,kJ/kg\,K$$

Which among the following is the boiler mounting?

The following data pertain to a single stage impulse steam turbine:
Nozzle angle $$=$$ $${20^ \circ };$$
Blade velocity $$= 200$$ $$m/s;$$
Relative steam velocity at entry $$= 350$$ $$m/s;$$
Blade inlet $$30;$$
Blade exit angle $$ = {25^ \circ }.$$

If blade friction is neglected, the work done per $$kg$$ steam is