Vayudoot Aviation

1. The squirrel cage tachometer employs?

A three phase AC generator producing a voltage proportional to RPM.

A three phase AC generator producing a signal frequency proportional to RPM.

External AC power supply modified by the speed sensor.

External DC power supply modified by the speed sensor.

2. A cylinder head temperature gauge measures?

All of the cylinders and averages the result.

The coolest cylinder only to preserve the sensor.

The hottest cylinder only.

All of the cylinders and sums the result.

3. The electrical supply for a basic thermocouple system is?

Provided from the essential services busbar.

Provided by a dedicated transformer.

Self generated by the SEEBECK effect.

Self generated by the inductive reactance method.

4. The RPM Indicator (or tachometer) of a piston engine can Include a small red are within the arc normally used (green arc). In the RPM range corresponding to this small red arc the?

Is minimum at this rating.

Rating is the maximum possible in continuous mode.

Rating is the minimum usable in cruise propeller efficiency.

Propeller generates vibration, continuous rating is forbidden.

5. A vibration monitoring system used ______ to measure ______ filters out unwanted _______, then indicates ________, to the pilot?

Radiometers, radial movement, frequencles, absolute frequency.

Accelerometers, axial movement, noise, relative amplltude.

Thermisters, radial movement, frequencies, absolute amplitude.

Accelerometers, radial movement, frequencies and noise, relative amplitude.

6. A vibration meter indicates?

Frequency.

Pitch.

Period.

Relative amplitude.

7. The electronic tachometer sensor is composed of?

A circular magnet with four poles.

The rotor of a single phase A.C. generator.

A notched wheel rotating in front of an electro-magnet.

The rotor of a three phase A.C. generator.

8. The measurement of the turbine temperature or of the EGT (Exhaust Gas Temperature) is carried out at the?

High pressure chamber intake.

Combustion chamber outlet.

High pressure turbine outlet.

Combustion chamber intake.

9. A full Authority Digital Engine Control (FADEC) has the following functions : 1. Flow regulation (fuel, decelerations and accelerations monitoring). 2. Automatic starting sequence. 3. Transmissions of engine data to the pilot's instruments. 4. Thrust management and protection of operation limits. 5. Monitoring of the thrust reversers. The combination regrouping all the correct statement is?

2, 4, 5.

1, 3, 5.

1, 3, 4, 5.

1, 2, 3, 4, 5.

10. The speed of rotation of the motor in a tacho-indicator is?

Proportional to tacho-generator output voltage.

Proportional to tacho-generator output frequency.

Constant.

Proportional to tacho-generator output current.

11. EPR is calculated by?

Subtracting LP compressor inlet pressure from JP turbine outlet pressure.

Diving LP turbine outlet pressure by LP compressor inlet pressure.

Diving HP turbine outlet pressure by air inlet pressure.

Dividing compressor inlet pressure by HP turbine outlet pressure.

12. What type of sensor is normally used to measure inlet air temperature where the signal is to be employed for altitude compensation in a conventional (non FADEC) engine fuel system?

Liquid expansion.

Bi-metalic.

Capacitive.

Resistive.

13. If a remote sensing pressure measurement system uses a ratiometer rather than an ammeter as its indicator, it will be?

More sensitive to line resistance changes.

Rendered unservicrable by line resistance changes.

Not affected by line resistance changes.

Less sensitive to line resistance changes.

14. A synchroscope is used on aircraft to?

Reduce the vibration of each engine.

Reduce the rpm of each engine.

Achieve optimum control of on-board voltages.

Set several engines to the same speed.

15. If a manifold pressure gauge consistently registers atmospheric pressure, the cause is probably?

Ice in Induction system.

Fuel of too low volatility.

Leak in pressure gauge line.

Too high float level.

16. The pointer that aligns with the red line on a EGT gauge?

Is movable and indicates maximum temperature exceeding the red line.

Indicates maximum temperature.

Is adjustable to permit higher limits to be set when taking-off at high mass in high mablent temperatures.

Is adjustable to permit different limits to be set as required.

17. A remote sensing pressure gauging system measuring low pressures, typically employs a ________ to move _________ The variation in ________ are then measured using a _________ or ___________?

Bellows, variable resister, resistance, wheatstone bridge, ratiometer.

Aneroid capsule, capacitor, capacitance, wheatstone bridge, ratiometer.

Bourden tube, variometer, capacitance, transistor, capacitor.

Differential capsule, ratiometer, current, capacitor, ammeter.

18. On an aeroplane equipped with a constant speed propeller, the RPM indicator enables?

Control of the propeller regulator and the display of propeller RPM.

Control of power.

On a twin-engine aeroplane, automatic engine synchronisation.

Selection of engine RPM.

19. The disadvantages of a single-phase A.C. generator tachometer are: 1. The pressure of spurious signals due to D.C. generator commutator. 2. The importance of line resistance on the information value. 3. The influence of temperature on the techometer information. The combination regrouping all the correct statements is?

1, 2, 3.

2.

1, 3.

1, 2.

20. Vibration meters measure?

Frequency in Hz.

Accelerations in g.

Amplitude at a given frequency.

Period in seconds.

21. A system which measures both torque and engine RPM employs?

A phonic wheel at each end of the output shaft, coupled to a device which measures frequency and voltage differences between the two outputs.

A phonic wheel and a tacho-generator. The phonic wheel detects torque and the tacho-generator detects RPM.

A tacho-generator at each end of the output shaft, coupled to a device which measures frequency and phase difference between the two output signals.

A phonic wheel at each end of the output shaft, coupled to a device which measures frequency and phase difference between the two outputs.

22. Torque can be determined by measuring the?

Frequency of an impulse tachometer attached to a transmission shaft.

Oil pressure at the fixed crown of an epicycloidal reducer of the main engine gearbox.

Quantity of light passing through a rack-wheel attached to a transmission shaft.

Phase difference between 2 impulse tachometers attached to a transmission shaft.

23. The advantages of an electrical induction tachometer are: 1. The display is not sensitive to line resistance. 2. The measurement is independent of aircraft power supply. 3. The measurement is independent of temperature variations. 4. The option to use without restriction several Indicators connected in parallel to a single transmitter. The combination regrouping all the correct statements is?

2, 3, 4.

1, 3, 4.

1, 2, 3, 4.

1, 2, 4.

24. The main advantage of a ratiometer-type temperature Indicator is that it?

Is very accurate.

Can operate without an electrical power supply.

Is simple.

Carries out an Independent measurement of the supply voltage.

25. The transmitter of RPM indicator may consist of: 1. A magnetic senor supplying an inducted AC voltage. 2. A DC generator supplying a DC voltage. 3. A single-phase AC generator supplying an AC voltage. 4. A three-phase AC generator supplying a three-phase voltage. The combination of correct statements is?

1, 2, 3.

2, 3, 4.

1, 2, 3, 4.

1, 4.

26. In order to measure temperature the cylinder had temperature (CHT) gauge utillses a?

Bourdon tube.

Thermocouple consisting of two dissimilar metals.

Wheatstone bridge circuit.

Ratiometer circult.

27. To permit turbine exit temperatures to be measured, gas turbines are equipped with thermometers which work on the following principle?

Gas pressure.

Thermocouple.

Liquid expansion.

Bi-metallic strip.

28. The operating principle of an "electronic" tachometer is to measure the?

Electromotive force (EMF) produced by a dynamo or an alternator.

Rotation speed of an asynchronous motor energized by an alternator.

Magnetic field produced by a dynamo or an alternator.

Frequency of the electric impulse created by a notched wheel rotating in a magnetic field.

29. Which of the following is least affected by variation in power supply voltage?

Galvanometers

Rheostats.

Ratiometers.

Variometers.

30. What is EPR in a turbofan engine?

The ratio of compressor inlet pressure to turbine outlet pressure.

The ratio of combustion chamber pressure to compressor inlet pressure.

The ratio of the integrated mean of LP turbine outlet pressure plus fan outlet pressure to the fan inlet pressure.

The ratio to HP turbine outlet pressure to Hp compressor inlet pressure.

31. If the EPR gauge over reads during the take-off run?

Climb performance will be improved.

There is a danger that the aircraft will fall to take-off safely.

The engines will not start.

The engine will exceed its limiting pressures and teperatures.

32. On what principles does a vibration meter work?

Accelerometers, amplitude filters, and comparators.

High frequency, low amplitude.

Accelerometers, frequency filters and amplifiers.

Dynamometers, frequency filters and amplifiers.

33. The temperature measured by the CHT (Cylinder Head temperature) probe is The?

Temperature within the hottest cylinder, depending on its position in the engine block.

Temperature of the carburetor to be monitored when the outside air temperature is between -5°C and 10° C.

Average temperature within the whole set of cylinders.

Temperature of the exhaust gases.

34. Where is EGT measured?

In the jet pipe.

At the turbine inlet.

In the combustion chamber.

At the turbine outlet.

35. Which of the following is used to measure temperature? 1. The seebeck effect. 2. the variation of electrical resistance with changes in temperature. 3. The variation of capacitance with changes in temperature. 4. Thermal expansion of liquids and solids.

1, 2, 3.

1, 4, 3.

1, 3, 4.

1, 2, 4.

36. The advantage of a D.C. generator tachometer are: 1. Easy transmission of the information. 2. Independence of the information relative to the airborne electrical power supply. 3. Freedom from any spurious current due to the commutator. The combination regrouping all the correct statements is?

1, 3.

1, 2.

1, 2, 3.

2, 3.

37. A mainfoid pressure gauge of piston engine measures?

Vacuum in the carburettor.

Absolute air pressure entering the carburettor.

Absolute pressure in intake system near the inlet valve.

Fuel pressure leaving the carburettor.

38. The pressure probe used to measure the pressure of a low pressure fuel pump is?

A differential capsule.

An anerold capsule.

A bellows sensor.

A Bourdon tube.

39. Turbo-prop engine torque is commonly measured using? 1. Rotary hydraulic systems. 2. Axial hydraulic systems. 3. Strain gauges. 4. Phase shifting phonic wheel systems

All of the above.

2, 3, 4.

1. 3, 4.

1, 2, 3.

40. The drag cup in a tacho-indicator?

Converts limited angular motion into rotation.

Converts AC input into rotary motion.

Converts rotary motion into limited angular displacement proportional to the variable being measured.

Overcomes the effects of internal friction within the Indicator.

41. The signal supplied by a transmitter fitted with a magnetic sensor, connected to an RPM indicator is a three-phase voltage frequency varies with RPM?

The indicator is a simple voltmeter with a rev/min scale measuring an AC voltage varying with the RPM?

The indicator converts the signal into pulses which are then counted.

The indicator is provided with a motor which drives a magnetic tachometer a DC voltage varying with the RPM.

The indicator rectifies the signal via a diode bridge and is provided with a voltmeter measuring an AC voltage, the frequency of which varies with the RPM.

42. The principle of detection of a vibration monitoring system is based on the use of?

A frequency converter.

2 high and low frequency filters.

2 accelerometers.

2 high and low frequency amplifiers.

43. The probe used to measure the air intake pressure of a gas turbine engined powerplant is?

A bellows sensor.

An anerold capsule.

A differential capsule.

A Bourdon tube.

44. Vibration sensors on a turbofan engine are typically located?

On the HP spool and by-pass duct.

Longitudinally pointing, on the fan and turbine casings.

Radially pointing on the fan and turbine casings.

On the gearboxes and output shafts.

45. Arrange the following sensors in increasing order of the pressures they would be used to sense? 1. Capsule, 2. Bellows. 3. Bourden tube.

2, 3, 1.

1, 2, 3.

1, 3, 2.

3, 1, 2.

46. What does the vibration measuring system indicate to the pilot?

Absolute frequency.

Relative amplitude.

Absolute magnitude.

Relative frequency.

47. Typical vibration sensors include? 1. Inductive coils. 2. Phonic wheels.3. Magnetometers. 4. Piezo crystals.

1, 3, 4.

1, 2, 4.

1, 4.

2, 4.

48. What type of sensors are typically used to measure engine oil temperature?

Thermocouples.

Resistive probes.

Capacitive probes.

Reactive probes.

49. Jet engine exhaust gas temperature is measured using?

A number of thermocouples connected in parallel.

A number of thermocouples connected in series.

A thermocouple.

A thermistor.

50. The yellow sector of the temperature gauge corresponds to?

An exceptional operating range.

A normal operating range.

A forbidden operating range.

A frequent operating range.

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