The air is delivered ________ in one revolution in case of a three lobbed rotor.
A). Two times
B). Three times
C). Four times
D). Six times
If V, U and Vr represent the absolute velocity of fluid, velocity of blade, and relative velocity of fluid, and suffix ‘I’ and ‘o’ stand for entry and exit conditions, then in a rotary machine whose degree of reaction is unity
A). Vi = Vo
B). Vt > Vo
C). U < Vo
D). V = Uo
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
A). p = (p + p)/2
B). p = p. p
C). P = Pa p/p
D). p = Pa p/p
In the aircraft propellers
A). The propulsive matter is caused to flow around the propelled body
B). Propulsive matter is ejected from within the propelled body
C). Its functioning does not depend on presence of air
D). All of the above
The axial flow compressor is preferred in aircraft gas turbines because of
A). Low frontal area
B). Higher thrust
C). High pressure rise
D). None of these