121. The basic principle of the rocket propulsion is the same as that of jet propulsion.
Yes
No
✅ The correct answer is option A.
Compressors, Gas Dynamics and Gas Turbines MCQs
122. The stagnation pressure rise in a centrifugal compressor takes place
in the diffuser only
in the impeller only
in the diffuser and impeller
in the inlet guide vanes only
✅ The correct answer is option C.
123. An axial compressor gives optimum performance at high speeds and large volume flows.
Agree
Disagree
✅ The correct answer is option A.
124. The efficiency of a jet engine is higher at
low speeds
high speeds
low altitudes
high altitudes
✅ The correct answer is option D.
126. In the aircraft propellers
the propulsive matter is ejected from within the propelled body
the propulsive matter is caused to flow around the propelled body
its functioning does not depend upon the presence of air
none of the above
✅ The correct answer is option A.
127. In a jet propulsion
the propulsive matter is ejected from within the propelled body
the propulsive matter is caused to flow around the propelled body
its functioning does not depend upon presence of air
none of the above
✅ The correct answer is option B.
128. For a two stage reciprocating compressor, compression from p1 to p3 is with perfect intercooling and no pressure losses. If compression in both the cylinders follows the same polytropic process and the atmospheric pressure is pa, then the intermediate pressure p2 is given by
p2 = (p1 + p3)/2
p2 = p1.p3
P2 = Pa x p3/p1
p2 = pa p3/p1
✅ The correct answer is option B.
129. Intercooling in gas turbines
decreases net output but increases thermal efficiency
increases net output but decreases thermal efficiency
decreases net output and thermal efficiency both
increases net output and thermal efficiency both
✅ The correct answer is option B.
130. In a centrifugal compressor, an increase in speed at a given pressure ratio causes
increase in flow
decrease in flow
increase in efficiency
increase in flow and decrease in efficiency
✅ The correct answer is option D.