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The auxiliary power unit APU has its own AC generator that ? Experience > landing

exemple question 154
Supplies aircraft with three phase 5 2 v 4 hz ac.


A magnetic circuit breaker is ?

exemple question 155
A magnetic circuit breaker A protection system that has a quick tripping response.


The advantages of alternating current on board an aircraft are 1 simple connection2 high starting torque3 flexibility in use4 lighter weight of equipment5 easy to convert into direct current6 ?

exemple question 156
The advantages of alternating current on board an aircraft are 1 simple connection2 high starting torque3 flexibility in use4 lighter weight of equipment5 easy to convert into direct current6 easy maintenance of machinesthe combination of correct statements A protection system that has a quick tripping response. Alternating current (ac) extremely versatile has following advantages over direct current ac can be simply efficiently changed from one voltage to another using a transformer ac generators are simpler in construction lighter the equivalent power output of a dc machine ac can be easily efficiently changed into dc using a rectifier.


exemple question 157
On board present aircraft batteries used are mainly cadmium nickel their advantages are 1 low risk of thermal runaway2 high internal resistance hence higher power3 good charging and discharging capability at high rating4 wider permissible temperature range5 good storage capability6 sturdiness owing to its metal casing7 electrolyte density remains unchanged during charging the combination of correct statement A protection system that has a quick tripping response. The terminal voltage remains substantially constant at about 1 2 volts throughout most of discharge due to its low internal resistance it also capable of supply high current during its discharge cycle low current during recharging without violent fluctuations of terminal voltage nicad batteries have a low thermal capacity heat generated in certain conditions faster than it can dissipate so causing rapid increase in temperature this has effect of lowering effective internal resistance thus allowing an ever increasing charging current which unless checked leads to total destruction of battery.


exemple question 158
A static inverter powered Direct current on input alternating current output. an inverter a unit used to convert dc into ac dc to ac inverter ac to dc rectifier.


exemple question 159
The voltage regulator of a dc generator connected in Series with shunt field coil. On a dc generator voltage regulation achieved changing voltage in voltage coil which changes carbon pile pressure which changes current in shunt field the voltage regulator connected in series with shunt field coil.


exemple question 160
During start of an engine fitted with a brushless ac generator with no commutator rings generator activated A set of permanent magnets. On a dc generator voltage regulation achieved changing voltage in voltage coil which changes carbon pile pressure which changes current in shunt field the voltage regulator connected in series with shunt field coil.


8
The type of windings commonly used in dc starter motors are A set of permanent magnets. Dc motors are classified as to ways in wich their field excitation circuits are arranged (series wound shunt wound compound wound) the series wound motors have their field armature windings in series with each other so same current flows through both adding them together these motors have a high starting torque especially as in initial stages there little back emf so all current used in them they are commonly used as starter motors.


9
The power output of a generator controlled Varying field strength. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load.


10
A relay A magnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load.


11
The voltage of a fully charged lead acid battery cell A magnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load.


12
The capacity of a battery given in A magnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load.


13
A relay An electromagnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load.


14
The most widely used electrical frequency in aircraft An electromagnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load.


15
If electrical load of an ac generator providing a constant output voltage increases voltage regulator will Increase intensity of excitation current. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded.


16
The so called 'hot buse or 'direct buse are Directly connected to battery. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded.


17
The reason using inverters in an electrical system To change dc into ac. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded.


18
The function of a constant speed drive csd to ensure That generator produces a constant frequency. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded.


19
A bus bar A distribution point electrical power. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded.


20
A csd of an ac generator may be disconnected in flight the primary reason s disconnection are Low oil pressure and/or high oil temperature of generator drive. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded.



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