21. When the cross-section of a nozzle __________ continuously from entrance to exit, it is called a convergent nozzle.
increases
decreases
✅ The correct answer is option B.
Steam Nozzles and Turbines MCQs
22. The efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine.
same
less
more
✅ The correct answer is option B.
23. In a reaction turbine when the degree of reaction is zero, then there is
no heat drop in moving blades
no heat drop in fixed blades
maximum heat drop in moving blades
maximum heat drop in f
✅ The correct answer is option A.
25. Reheating of steam in a turbine
increases the workdone through the turbine
increases the efficiency of the turbine
reduces wear on the blades
all of these
✅ The correct answer is option D.
26. The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam.
more
less
✅ The correct answer is option B.
27. The expansion of steam in a nozzle follows
Carnot cycle
Rankine cycle
Joule cycle
Stirling cycle
✅ The correct answer is option B.
28. The density of supersaturated steam is about __________ that of the ordinary saturated vapour at the corresponding pressure.
same as
2 times
4 times
8 times
✅ The correct answer is option D.
29. Rateau turbine is
simple reaction turbine
velocity compounded turbine
pressure compounded turbine
pressure-velocity comp
✅ The correct answer is option C.
30. The velocity of steam, in reaction turbines, is increased in the fixed blades as well as in moving blades.
TRUE
FALSE
✅ The correct answer is option A.