Random question and answer

c

During engine operation, if carburetor heat is applied, it will
a. Increase air-to-fuel ratio
b. Increase engine rpm
c. decreases the air density to the carburetor
d. decrease rpm

d

Which of the following required the least mass flow rate in order for it to function efficiently?
a. turbojet
b. ramjet
c. scramjet
d. rocket

b

What is the purpose of the supersonic diffuser in the variable throat valve?
a. final reduction in velocity prior to compressor face
b. Interim reduction in velocity to below Mach 1 prior to a further reduction in the subsonic diffuser
c. Interim reduction in velocity to below Mach 0.5 prior to a further reduction in the subsonic diffuser
d. Increase in velocity prior to compressor face.

c

The effect of the temperature and pressure of the gases as they pass across the turbine is
a. their temperature decreases, and their pressure rises
b. Both their temperature and pressure increases
c. both their temperature and pressure decreases
d. the temperature increases in their pressure falls.

c

Compressor blades increase in size
a. from the root to the tip to increase the temperature
b. from the high - pressure section of the compressor to the high-pressure section to maintain a constant airflow velocity
c. from the high-pressure section of the compressor to the low-pressure section
d. from the tip to the root to decrease the temperature

a

In a by-pass engine, the by-pass air.
a. Increases the air mass flow are therefore increases the propulsive efficiency
b. Cools the combustion chamber and therefore increases the thermal efficiency
c. Reduces the air mass flow and therefore increases the propulsive efficiency
d. increases the air mass flow and therefore reduces the propulsive efficiency

b

A substance that has no fixed shape and yields easily to external pressure; a gas or a liquid. A substance that is able to flow easily.
a. Heat
b. Fluid
c. thermodynamic property
d. water

a

Cam-ground pistons are installed in some aircraft engines to
a. Provide a better fit at operating temperatures
b. Act as a compensating feature so that a compensated magneto is not required
c. Equalize the wear on all pistons
d. For proper movement of the connecting rod translated to the movement of piston

d

From a standing start with an increase in forward speed jet thrust will 
a. Increase
b. decrease
c. stay the same
d. Decrease then recover but will never achieve its initial setting 

a

The highest pressure in a gas turbine engine occurs
a.Between the compressor and the combustion chamber
b. In the combustion chamber
c. In the jet pipe
d. At the P1 probe

a

Cam-ground pistons are installed in some aircraft engines to 
a. Provide a better fit at operating temperatures
b. Act as a compensating feature so that a compensated magneto is not required
c. Equalize the wear on all pistons
d. For proper movement of the connecting rod translated to the movement of piston

d

The mean effective pressure of an ideal air-standard Diesel cycle can be increased by
a. Increasing the size of the intake and exhaust valve
b. Increasing the heat transfer into the engine cycle
c. Increasing the volume of the fuel injected
d. Increasing the engine displacement

b

The number of pounds of air present in the engine cylinder per pound of fuel is called 
a. Air specific weight ratio
b. Air-fuel ratio
c. Combustion efficiency
d. Fuel-air mixture

b

An un-supercharged aircraft reciprocating engine, operated at full throttle from sea level to 10,000 feet, provided the RPM is unchanged, will 
a. Lose power due to the reduced volume of air drawn into the cylinders
b. Lose power due to the reduced density of the air drawn into the cylinders
c. Produce constant power due to the same volume of air drawn into the cylinders
d. Remains the same as on sea level condition 

d

For a piston engine, the ratio of the brake horsepower to the indicated horsepower is 
a. Thermal Efficiency
b. Propulsive Efficiency
c. Volumetric Efficiency
d. Mechanical Efficiency