The engine instrument utilising an aneroid pressure diaphragm is the ?
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To permit turbine exit temperatures to be measured gas turbines are equipped with thermometers which work on the following principle ?
A 'Bourdon Tube' is used in ?
If an epr set at a constant barometric pressure with an increasing oat thrust Manifold pressure gauge. Thrust the force generated the engines thrust the acceleration of a mass of air thrust = mass x acceleration mass = density x volume therefore a decrease in density due to an increasing oat would result in less mass being accelerated therefore a decrease in thrust but engine management system does trim fuel automatically to maintain selected thrust settings changes in oat. 
In a compensated capacitance type quantity indicating system contents gauge of a half full fuel tank indicates a fuel mass of 8000 kg if a temperature rise increased volume of fuel 5% indicated fuel mass would Manifold pressure gauge. the capacity of a capacitor depends on nature of dielectric in which it immersed fuel has twice capacitance of air so a full tank has twice capacitive reactance as en empty one if a temperature rise increases fuel volume fuel weight remains same. 
On an multi engine aircraft a synchroscope used to 1 reduce structural vibration and noise2 have symmetrical thrust and fuel consumption correct 2 incorrect. Cqb15 august 2012 the purpose of a synchroscope to reduce structural vibration noise the synchronizing system ensures that propeller speeds are all same this achieved an electrical system that compares speed signals from engine mounted generators out of balance signals using one engine as a master signal are automatically corrected electrically trimming engine speeds until all signals are equal. 
The basic principle of a capacitance fuel gauge system that Capacity of a capacitor depends on nature of dielectric in which it immersed. a capacitance type fuel gauge system consists of a variable capacitor located in fuel tank an amplifier an indicator the complete circuit forms an electrical bridge which continuously being rebalanced as a result of differences between capacitances of tank capacitor a reference capacitor the signal produced due to differences in signals amplified to operate a motor the motor then drives pointer to indicate capacitance change of tank capacitor thus change in fuel quantity indicated we have seen basic construction of this system now let us discuss how electrical capacitance principle utilized the capacitance type fuel gauge system in aircraft the capacitors which are to be installed in fuel tanks the fuel quantity measurement must be different in construction from those normally employed in electrical equipment the plates of capacitors take form of two tubes mounted concentrically with a narrow air space between them these plates extend full depth of a fuel tank capacitance depends on some factors which are area of plates distance between two plates the dielectric constant of material between two plates of capacitors now in this capacitance type fuel gauge system two factors plate area distance between plates are fixed the dielectric here the fuel in tank of aircraft the flow of a momentary current into a capacitor establishes a potential difference across its plates the dielectric i e fuel in aircraft's fuel tanks contains no free electrons so current cannot flow through it but it should be remembered that potential difference sets up a state of stress in atoms comprising it. Question 40-8
Assuming that cas remains constant if total pressure probe blocked ias Remains constant during level flight increases during a climb decreases during a descent. with a blocked pitot pressure in capsule fixed (like an altimeter) when aircraft climbs the static in case decreases capsule expands the reading on instrument increases (like an altimeter) to hold ias constant in climb (i e not allow capsule to expand) actual airspeed will have to decrease remember that with a blocked pitot asi over reads in climb under reads in descent with constant ias blocked pitot real ias and therefore tas will decrease until aircraft stalls. Question 40-9
Gas turbine engine rotational speed rpm usually sensed using either A 3 phase ac tachometer generator or an ac phonic wheel system. with a blocked pitot pressure in capsule fixed (like an altimeter) when aircraft climbs the static in case decreases capsule expands the reading on instrument increases (like an altimeter) to hold ias constant in climb (i e not allow capsule to expand) actual airspeed will have to decrease remember that with a blocked pitot asi over reads in climb under reads in descent with constant ias blocked pitot real ias and therefore tas will decrease until aircraft stalls. Question 40-10
The output from an engine vibration transducer Always filtered to remove unwanted frequencies. virations are picked up accelerometers so you measure accelerations (piezzo electric or capacity type pickups) giving after conversion displacement / square second a first integration will give displacement speed (displacement per second) a second integration will give displacement each integration may introduce or amplify measurement errors but initial acceleration signal not practical use depending on engine type the bearing location displacement speed (usually noted in inch per second ips) used the vibration frequency filtered the cockpit indication to indicate only vibration in a frequency band corresponding to spool speed n1 n2 n3 that's why engines can have vibrations which are not related to spools rotating speed not being indicated in cockpit. Question 40-11
The sensor s feeding epr indicator are Pressure probes one located upstream from compressor inlet the other downstream from turbine outlet. virations are picked up accelerometers so you measure accelerations (piezzo electric or capacity type pickups) giving after conversion displacement / square second a first integration will give displacement speed (displacement per second) a second integration will give displacement each integration may introduce or amplify measurement errors but initial acceleration signal not practical use depending on engine type the bearing location displacement speed (usually noted in inch per second ips) used the vibration frequency filtered the cockpit indication to indicate only vibration in a frequency band corresponding to spool speed n1 n2 n3 that's why engines can have vibrations which are not related to spools rotating speed not being indicated in cockpit. Question 40-12
The rpm indicator or tachometer of a piston engine can include a small red arc within arc normally used green arc in rpm range corresponding to this small red arc Propeller generates vibration continuous rating forbidden. virations are picked up accelerometers so you measure accelerations (piezzo electric or capacity type pickups) giving after conversion displacement / square second a first integration will give displacement speed (displacement per second) a second integration will give displacement each integration may introduce or amplify measurement errors but initial acceleration signal not practical use depending on engine type the bearing location displacement speed (usually noted in inch per second ips) used the vibration frequency filtered the cockpit indication to indicate only vibration in a frequency band corresponding to spool speed n1 n2 n3 that's why engines can have vibrations which are not related to spools rotating speed not being indicated in cockpit. Question 40-13
A three phase electrical tachometer consists of A three phase generator a synchronous motor a magnetic tachometer. virations are picked up accelerometers so you measure accelerations (piezzo electric or capacity type pickups) giving after conversion displacement / square second a first integration will give displacement speed (displacement per second) a second integration will give displacement each integration may introduce or amplify measurement errors but initial acceleration signal not practical use depending on engine type the bearing location displacement speed (usually noted in inch per second ips) used the vibration frequency filtered the cockpit indication to indicate only vibration in a frequency band corresponding to spool speed n1 n2 n3 that's why engines can have vibrations which are not related to spools rotating speed not being indicated in cockpit. Question 40-14
Cas can be obtained from following data Eas pressure altitude. to get from cas via eas to tas we use pressure altitude temperature to go back from tas via eas to cas we would again use pressure altitude temperature eas cas corrected compressibiliy compressibility related to pressure altitude. Question 40-15
The properties of a single phase electrical tachometer are 1 indication depending on line resistance2 independance from aircraft airborne power supply3 simple designthe combination that regroups all of correct statements Eas pressure altitude. a single phase electrical tachometer (inductive probe) requires an external power supply signal processing the indication depends on line resistance it a simple design tachometer. Question 40-16
Concerning a fuel gauge system a pilot more interested the Mass of fuel than volume of fuel. a single phase electrical tachometer (inductive probe) requires an external power supply signal processing the indication depends on line resistance it a simple design tachometer. Question 40-17
A float type fuel gauge 1 gives a mass information 2 gives information independent of aircraft's manoeuvres and attitude changes 3 gives information all more accurate as tank full 4 typically a dc powered system the combination that regroups all of correct statements Mass of fuel than volume of fuel. a single phase electrical tachometer (inductive probe) requires an external power supply signal processing the indication depends on line resistance it a simple design tachometer. Question 40-18
A magnetic tachometer consists of A permanent magnet turning inside a non magnetic drag cup. Magnetic tachometer the magnetic tachometer consists of rotary bell shaped permanent magnet (1) core (2) between which there a narrow gap arranged in this gap hollow aluminum cylinder (3) held against rotation coil spring (4) the rotating magnetic field induces currents in cylinder (3) which tend to rotate cylinder with a force whose torque proportional to speed of rotation of magnet (1) a scale with uniform divisions engraved on outside circumference of cylinder (3) it indicates speed (rpm) of magnet (1) of shaft whose speed to be measured in opening (5). Question 40-19
Given following parameters in a capacitance fuel gauge correct formula a = area of platesd = distance between platese = dielectric permittivity Capacitance = e x a / d. Magnetic tachometer the magnetic tachometer consists of rotary bell shaped permanent magnet (1) core (2) between which there a narrow gap arranged in this gap hollow aluminum cylinder (3) held against rotation coil spring (4) the rotating magnetic field induces currents in cylinder (3) which tend to rotate cylinder with a force whose torque proportional to speed of rotation of magnet (1) a scale with uniform divisions engraved on outside circumference of cylinder (3) it indicates speed (rpm) of magnet (1) of shaft whose speed to be measured in opening (5). Question 40-20
A three phase electrical tachometer utilises a generator feeding A synchronous motor turning a drag cup. The electrical generator system utilises a small three phase tachometer generator driven the engine the output of this generator then taken to an indicator which consists of a synchronous motor turning a drag cup assembly which moves a pointer over a scale as in mechanical system three phase electrical tachometer. Question 40-21
The operating principle of an inductive probe tachometer to measure Frequency of electric impulse created a notched wheel rotating in a magnetic field. The electrical generator system utilises a small three phase tachometer generator driven the engine the output of this generator then taken to an indicator which consists of a synchronous motor turning a drag cup assembly which moves a pointer over a scale as in mechanical system three phase electrical tachometer. Question 40-22
The unit used to measure capacitance of a capacitor the Frequency of electric impulse created a notched wheel rotating in a magnetic field. the farad (symbol 'f') the si derived unit of capacitance the unit named after english physicist michael faraday a farad the charge in coulombs which a capacitor will accept the potential across it to change 1 volt a coulomb 1 ampere second example a capacitor with capacitance of 47 nf will increase 1 volt per second with a 47 na input current. Question 40-23
Any vibration displayed on an engine vibration monitoring system a turbojet Indicates rotor imbalance. The engine vibration monitoring on a turbojet engine indicates any vibration resulting from an imbalance on rotation parts of engine engine vibration may occur due to fan blade/spinner icing resulting in a rotor imbalance. Question 40-24
6000 psi approximately equivalent to Indicates rotor imbalance. 1 psi (pound per square inch) = 0 07 bar 1 bar = 15 psi. Question 40-25
1 bar equals how many pascals Indicates rotor imbalance. 1 bar = 100000 pa (pascal) = 1000 hpa (hectopascal). Question 40-26
What the relation between c and k c celsius° k kelvin Indicates rotor imbalance. fahrenheit = 1 8 x c + 32 kelvin = c + 273 15. Question 40-27
Which of these statements about temperature units are correct or incorrect 1 +20° celsius = 68° fahrenheit2 0° celsius = 273 15° kelvin I correct ii correct. fahrenheit = 1 8 x c + 32 kelvin = c + 273 15. Question 40-28
Which of these statements are correct or incorrect 1 +15° celsius = 273 15° kelvin2 +15° celsius = 59° fahrenheit I incorrect ii correct. fahrenheit = 1 8 x c + 32 kelvin = c + 273 15. Question 40-29
Which statement correct regarding relation between kelvin k fahrenheit f and celcius c temperatures 1 k = c 273 152 f = 1 8 x c + 32 I incorrect ii correct. fahrenheit = 1 8 x c + 32 kelvin = c + 273 15. Question 40-30
Which of these statements are correct or incorrect 1 +15° celsius = 288 15° kelvin2 +15° celsius = 59° fahrenheit I correct ii correct. fahrenheit = 1 8 x c + 32 kelvin = c + 273 15. Question 40-31
The correct relation I correct ii correct. Cqb15 february 2012 1 kg = 2 2 lbs 0 45 kg = 1 lb. Question 40-32
A pressure of 1013 25 hpa corresponding to I correct ii correct. a pressure of 1013 25 hpa corresponding exactly to 14 69596432068 psi 29 92 inches of mercury. Question 40-33
Given q = charge coulombs u = potential difference between plates volt c= capacitance farads the correct relationship between these parameters I correct ii correct. chrism should u not read v instead to comply with standard notation it should but we do not write questions we do not modify them this the official wording coulomb the quantity of electricity transported in 1 second a current of 1 ampere c the capacitance u the stored energy. Question 40-34
20 bar approximately equal to I correct ii correct. 1 psi (pound per square inch) = 0 07 bar 1 bar = 15 psi. Question 40-35
The relation between c and k c celsius° k kelvin I correct ii correct. fahrenheit = 1 8 x c + 32 kelvin = c + 273 15. Question 40-36
A pressure of 200 bar equivalent to approximately I correct ii correct. 1 psi (pound per square inch) = 0 07 bar 1 bar = 15 psi. Question 40-37
Changes in temperature of fuel affect its density volume and dielectric value er a decrease in temperature causes A decreases in volume increases in density increases in er. Revised ecqb03 july 2016 warning! this question also exists at examm with end statement an increase in temperature causes in this case answer an increase in volume decrease in density decrease in er mnemonic decrease in temperature = d i i increase in temperature = i d d. Question 40-38
On a multi engine aircraft a synchroscope provides An automatic and/or a visual system to synchronize propellers rotation speeds. Cqb15 may 2012 on a multi engined aircraft a synchronizing system ensures propeller speeds are all same this achieved an electrical system that compares speed signals from engine mounted generators out of balance signals using one engine as a master signal are automatically corrected electrically trimming engine speeds until all signals are equal. Question 40-39
The parameters used to represent thrust are 1 n1 low pressure shaft speed 2 n2 high pressure shaft speed 3 egt4 eprthe combination that regroups all of correct statements An automatic and/or a visual system to synchronize propellers rotation speeds. Cqb15 may 2012 on a multi engined aircraft a synchronizing system ensures propeller speeds are all same this achieved an electrical system that compares speed signals from engine mounted generators out of balance signals using one engine as a master signal are automatically corrected electrically trimming engine speeds until all signals are equal. Question 40-40
Which statement about fuel flow are correct or incorrect i fuel flow may be measured volume per unit of time ii fuel flow may be measured mass per unit of time I correct ii correct. Cqb15 may 2012 units used fuel flow when measured volume per hour are liters/hour us gallons/hour units used fuel flow when measured mass per hour kilogrammes/hour pounds/hour.
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