Compressors, Gas Dynamics and Gas Turbines Online Test – Multiple Choice Questions and Answers 1. A turbo-prop is preferred to turbo-jet because it can fly at super sonic speeds it has high propulsive efficiency at high speeds it has high power for take off it can fly at high elevations 2. The minimum work required for a three stage reciprocating air compressor is __________ the work required for each stage three times equal to double six times 3. The overall isothermal efficiency of the compressor is defined as the ratio of volume of free air delivery per stroke to the swept volume of the piston isentropic power to the power required to drive the compressor work required to compress the air isothermally to the actual work required to compress the air for the same pressure ratio isothermal power to the shaft power or B.P. of the motor or engine required to drive the compressor 4. The air power of the compressor is also known as frictional power brake power indicated power none of these 5. In a high pressure compressor, the delivery pressure is 8 to 10 bar 1 to 5 bar 5 to 8 bar 10 to 15 bar 6. The ratio of the net work obtained from the gas turbine plant to the turbine work is known as work ratio pressure ratio compression ratio none of these 7. Which of the following statement is correct relating to rocket engines ? The exit velocities of exhaust gases are much higher than those in jet engine The combustion chamber in a rocket engine is directly analogous to the reservoir of a super sonic wind tunnel The stagnation conditions exist at the combustion chamber all of the above 8. For minimum work required to compress and deliver a quantity of air by multi-stage compression, the intercooling should be perfect the compression ratio in each stage should be same the workdone in each stage should be same all of the above 9. A jet engine has no propeller propeller in front propeller at back propeller on the top 10. A rocket engine uses __________ for the combustion of its fuel surrounding air its own oxygen compressed atmospheric air none of these Loading … Question 1 of 10
