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24 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Why stranded wire used rather than solid wire in most power plant electrical systems? |
Solid wires will likely break when subjected to vibration |
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What 2 things must be considered in selection of a wire size when making an electrical installation in an aircraft |
The wire current carrying capacity and the voltage drop caused by the current flow |
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Why are the wires in certain electrical installation twisted together? |
To minimize the interference of the magnetic fields caused by current flowing the wires. |
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What is used to protect the wire bundle from chafing where it passes through a hole in a bulkhead or frame? |
Grommets around the edges of the hole |
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How are electrical wires protected when they pass through an area of high temperature? |
Insulated with a high temperature resistant insulation and passed through a protective conduit |
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What is the minimum separation that is allowed between a wire bundle and a fluid line that carries combustible fluid or oxygen? |
6 inches |
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What is the significance of the color of the solderless connectors that are used on electrical wires? |
It signifies the size of the wire that the connector will fit |
Red fits 22 to 18 gage wires Blue fits 16 to 14 gage wires Yellow fits 12 to 10 gage wires |
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What is the maximum number of wire terminals that can be stacked on a single stud in a terminal strip? |
4 |
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What is the purpose of the shielding that is used to encase some electrical wires? |
It intercepts the radiated electromagnetic energy and carries it to ground so it doesn't interfere with the nearby sensitive electronic equipment |
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Why must a switch be derated if it's used in the circuit controlling a DC electric motor? |
Because of the high current in-rush of the initial current |
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What is used as the rectifier to produce direct current in a DC generator? |
Brushes and commutators |
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How does a vibrator-type voltage regulator control the output voltage of a DC generator? |
By opening and closing the contacts when the voltage rises and drops above or below the regulated value bring a resistor in and out of the generator field circuit as required to regulate the output voltage |
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What is meant by paralleling the generator of a twin engine aircraft? |
Sharing the load equally between the generators by regulating the voltage |
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What is meant by flashing the field of a DC generator? |
Restoring residual magnetism into the generator frame by passing battery current through the field coils in the same direction current will flow when the generator is producing current. |
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What kind of rectifier is used in the DC alternator of the type that is used on most of the modern light airplanes? |
Full-wave 3 phase 6 silicon diodes |
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What is used to maintain a constant frequency of the alternating current that is produced by an AC alternator driven by an aircraft turbine engine |
A hydraulic constant speed drive unit between the engine and the alternator |
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What three things must be synchronized before a 3 phase AC generator can be connected to a bus that is being served by another generator? |
The voltage, frequency, and phase rotation of the generators |
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What must be done to reverse the direction of rotation of an armature of a DC electric motor? |
Reverse the current either through the field winding or the amature, never both |
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Does a series-wound DC motor have a high or low starting torque? |
High starting torque |
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Which aircraft electrical circuit does not normally contain a fuse or circuit breaker? |
The starter motor circuit |
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When removing a battery from an aircraft which connection should be removed first? |
The negative or ground connection |
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What is meant by an effective voltage of a sine wave alternating current? |
The value of the alternating current that is needed to produce the same amount of heat as this value of a direct current |
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What is the starter-generator that is used with many of the smaller gas turbine engines? |
A single engine mounted component that serves both as a starter for starting the turbine engine, when the engine is running it then converts its circuit into a compound wound generator supplying power to the bus |
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When should I craft wiring be installed in a conduit? |
When it goes to an area that the aircraft wiring would be exposed to damage such as the wheel well |
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