Term
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Definition
A class of physical phenomena arising from the existence and interactions of electric charges. |
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Term
What are atoms composed of? |
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Definition
Neutrons, protons, and electrons. |
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Term
List four examples of insulators. |
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Definition
Wood, rubber, plastic, and glass. |
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Term
List four examples of conductors. |
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Definition
Platinum, gold, copper, and silver. |
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Term
Where are semiconductors normally used? |
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Definition
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Term
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Definition
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Term
Define electrical current. |
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Definition
The movement of electrons through a conductor. |
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Term
What factors affect the amount of resistance in a conductor? |
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Definition
The type of material used, temperature, and the size. |
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Term
What unit of measurement is used to express electrical power? |
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Definition
Resistors control the amount of current flow in a circuit. |
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Term
What is the purpose of a resistor? |
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Definition
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Term
What is a simple definition of magnetism? |
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Definition
The ability of a substance to attract. |
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Term
How are artificial magnets classified? |
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Definition
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Term
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Definition
The ease of ability to conduct magnetic lines of force. |
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Term
What is residual magnetism? |
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Definition
The amount of magnetism that remains in a temporary magnet. |
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Term
How is magnetism induced in magnetic material? |
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Definition
The magnetic material may be placed in a magnetic field or brought into contact with another magnet. |
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Term
Can magnetic lines of force be insulated? |
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Definition
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Term
What are the three most commonly used shapes of magnets? |
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Definition
Bar, ring, and horseshoe. |
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Term
How can a magnet be weakened? |
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Definition
Heating or excessive jarring. |
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Term
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Definition
A term for magnetic lines of force. |
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Term
How is electromagnetism developed? |
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Definition
By current of electricity. |
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Term
When current flows through a conductor, does a magnetic field exist? |
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Definition
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Term
What must be known to apply the “left hand rule”? |
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Definition
The direction of the current flow. |
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Term
What rule is used to determine the flux direction of a wire in a loop? |
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Definition
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Term
How can an electromagnet’s field strength be increased? |
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Definition
By using a few turns of wire carrying a larger current or using many turns of wire carrying a small current. |
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Term
Why is alternating current used as the primary electrical power source in aircraft? |
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Definition
Less power is lost during transmission and the elimination of insulation and brushes |
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Term
What is the unit of measurement for frequency? |
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Definition
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Term
Define phase relationship. |
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Definition
A condition in which two moving objects are changing in, or out, of step. |
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Term
What are the two classifications of AC generation systems? |
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Definition
Variable-frequency and constant-frequency. |
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Term
What frequency has been established for AC power generation on aircraft? |
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Definition
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Term
How is voltage induced in a brush-type generator? |
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Definition
DC from an integral exciter generator is passed through windings on the rotor. |
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Term
What are the three generators that make up a brushless AC generator? |
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Definition
A permanent magnet generator, an AC exciter generator, and the main AC generator. |
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Term
What weak point was eliminated by the design of a brushless-type generator? |
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Definition
Arcing (which more easily occurs in rarefied air). |
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Term
What are the two main components of an AC generator? |
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Definition
Rotor assembly and stator. |
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Term
What three components make up the stator? |
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Definition
PMG armature, exciter field, and main armature windings. |
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Term
What are the two functions of the CSD governor system? |
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Definition
To control the drive output speed and equalize the load between generators operating in parallel. |
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Term
If CSD output rotation drives the generator below 365 Hz, what component causes the generator to be removed from the bus? |
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Definition
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Term
If the CSD temperature rises to an overheat condition, what should be done to prevent further damage? |
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Definition
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Term
What is installed on most IDGs to provide for easier installation and removal? |
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Definition
A quick attach-detach clamp. |
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Term
What are the typical functions of a GCU? |
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Definition
Voltage regulation, frequency and load control, real and reactive load division, over/underexcitation protection, over/underfrequency protection, open phase protection, reverse power protection, differential current protection, engine underspeed protection, generator circuit breaker and bus tie breaker control, no-break power transfer, and generator disconnect control |
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Term
How is voltage regulation and current limiting accomplished in the GCU? |
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Definition
By varying the generator excitation field |
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Term
How does the frequency and load controller for each generator system regulate the frequency of the generator CSD? |
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Definition
By controlling the magnetic trim head governor on the CSD. |
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Term
Why are protective devices installed in aircraft electrical systems? |
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Definition
For protection against short circuits and system faults |
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Term
How much time must pass before resetting a trip-free type circuit breaker? |
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Definition
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Term
What is the purpose of a current limiter? |
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Definition
To provide protection against fault currents on power distribution circuits. |
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Term
What are the internal components of a battery? |
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Definition
Plates, separators, and electrolyte |
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Term
What are the primary causes of premature failure of the lead-acid battery? |
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Definition
Abuse, overcharge, low solution, undercharge, and mountings |
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Term
What is the fundamental unit of the nickel-cadmium battery? |
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Definition
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Term
How are nickel-cadmium cells constructed? |
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Definition
By inserting positive and negative plates in plastic cases with separators of nylon and cellophane. |
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Term
When does a nickel-cadmium battery’s electrolyte reach its maximum level? |
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Definition
When the battery is fully charged |
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Term
How are motors classified? |
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Definition
By voltage, current used (AC or DC), and methods of motor excitation. |
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Term
How can the direction of rotation for a series motor be changed? |
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Definition
By reversing the current flow in a field winding or reversing current flow in the armature |
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Term
What advantage does the series motor have over other types of motors? |
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Definition
It operates on AC or DC excitation. |
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Term
How is the field winding of a shunt motor connected with the armature? |
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Definition
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Term
What type of transformer-rectifier is used in many aircraft to charge a nickel-cadmium battery? |
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Definition
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Term
What is another name for a transformer-rectifier? |
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Definition
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Term
List the electrical characteristics that can be measured using a multimeter. |
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Definition
AC volts, DC volts, current, resistance and frequency in some meters |
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Term
How is the position of the decimal on the display changed? |
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Definition
By changing the range of the multimeter |
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Term
Explain the HOLD function on the fluke multimeter. |
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Definition
This mode gives you the ability to take measurements that are difficult or hazardous to reach without taking your eyes off the test leads |
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Term
How should the leads be connected to a circuit? |
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Definition
Common (black) first and positive (red) second |
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