Shared Flashcard Set

Details

Vol 2 Section Review
Unit 5
59
Other
Not Applicable
02/11/2012

Additional Other Flashcards

 


 

Cards

Term
Define electricity.
Definition
A class of physical phenomena arising from the existence and interactions of electric charges.
Term
What are atoms composed of?
Definition
Neutrons, protons, and electrons.
Term
List four examples of insulators.
Definition
Wood, rubber, plastic, and glass.
Term
List four examples of conductors.
Definition
Platinum, gold, copper, and silver.
Term
Where are semiconductors normally used?
Definition
In solid-state devices.
Term
What is EMF?
Definition
Electromotive force.
Term
Define electrical current.
Definition
The movement of electrons through a conductor.
Term
What factors affect the amount of resistance in a conductor?
Definition
The type of material used, temperature, and the size.
Term
What unit of measurement is used to express electrical power?
Definition
Resistors control the amount of current flow in a circuit.
Term
What is the purpose of a resistor?
Definition
Watts.
Term
What is a simple definition of magnetism?
Definition
The ability of a substance to attract.
Term
How are artificial magnets classified?
Definition
Permanent or temporary.
Term
What is permeability?
Definition
The ease of ability to conduct magnetic lines of force.
Term
What is residual magnetism?
Definition
The amount of magnetism that remains in a temporary magnet.
Term
How is magnetism induced in magnetic material?
Definition
The magnetic material may be placed in a magnetic field or brought into contact with another magnet.
Term
Can magnetic lines of force be insulated?
Definition
No.
Term
What are the three most commonly used shapes of magnets?
Definition
Bar, ring, and horseshoe.
Term
How can a magnet be weakened?
Definition
Heating or excessive jarring.
Term
Define flux.
Definition
A term for magnetic lines of force.
Term
How is electromagnetism developed?
Definition
By current of electricity.
Term
When current flows through a conductor, does a magnetic field exist?
Definition
Yes.
Term
What must be known to apply the “left hand rule”?
Definition
The direction of the current flow.
Term
What rule is used to determine the flux direction of a wire in a loop?
Definition
The left-hand rule.
Term
How can an electromagnet’s field strength be increased?
Definition
By using a few turns of wire carrying a larger current or using many turns of wire carrying a small current.
Term
Why is alternating current used as the primary electrical power source in aircraft?
Definition
Less power is lost during transmission and the elimination of insulation and brushes
Term
What is the unit of measurement for frequency?
Definition
Hertz.
Term
Define phase relationship.
Definition
A condition in which two moving objects are changing in, or out, of step.
Term
What are the two classifications of AC generation systems?
Definition
Variable-frequency and constant-frequency.
Term
What frequency has been established for AC power generation on aircraft?
Definition
400 hertz.
Term
How is voltage induced in a brush-type generator?
Definition
DC from an integral exciter generator is passed through windings on the rotor.
Term
What are the three generators that make up a brushless AC generator?
Definition
A permanent magnet generator, an AC exciter generator, and the main AC generator.
Term
What weak point was eliminated by the design of a brushless-type generator?
Definition
Arcing (which more easily occurs in rarefied air).
Term
What are the two main components of an AC generator?
Definition
Rotor assembly and stator.
Term
What three components make up the stator?
Definition
PMG armature, exciter field, and main armature windings.
Term
What are the two functions of the CSD governor system?
Definition
To control the drive output speed and equalize the load between generators operating in parallel.
Term
If CSD output rotation drives the generator below 365 Hz, what component causes the generator to be removed from the bus?
Definition
Underspeed switch.
Term
If the CSD temperature rises to an overheat condition, what should be done to prevent further damage?
Definition
Disconnect the CSD.
Term
What is installed on most IDGs to provide for easier installation and removal?
Definition
A quick attach-detach clamp.
Term
What are the typical functions of a GCU?
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
Term
How is voltage regulation and current limiting accomplished in the GCU?
Definition
By varying the generator excitation field
Term
How does the frequency and load controller for each generator system regulate the frequency of the generator CSD?
Definition
By controlling the magnetic trim head governor on the CSD.
Term
Why are protective devices installed in aircraft electrical systems?
Definition
For protection against short circuits and system faults
Term
How much time must pass before resetting a trip-free type circuit breaker?
Definition
One minute.
Term
What is the purpose of a current limiter?
Definition
To provide protection against fault currents on power distribution circuits.
Term
What are the internal components of a battery?
Definition
Plates, separators, and electrolyte
Term
What are the primary causes of premature failure of the lead-acid battery?
Definition
Abuse, overcharge, low solution, undercharge, and mountings
Term
What is the fundamental unit of the nickel-cadmium battery?
Definition
The cell.
Term
How are nickel-cadmium cells constructed?
Definition
By inserting positive and negative plates in plastic cases with separators of nylon and cellophane.
Term
When does a nickel-cadmium battery’s electrolyte reach its maximum level?
Definition
When the battery is fully charged
Term
How are motors classified?
Definition
By voltage, current used (AC or DC), and methods of motor excitation.
Term
How can the direction of rotation for a series motor be changed?
Definition
By reversing the current flow in a field winding or reversing current flow in the armature
Term
What advantage does the series motor have over other types of motors?
Definition
It operates on AC or DC excitation.
Term
How is the field winding of a shunt motor connected with the armature?
Definition
In parallel.
Term
What type of transformer-rectifier is used in many aircraft to charge a nickel-cadmium battery?
Definition
Special T-R.
Term
What is another name for a transformer-rectifier?
Definition
Converter
Term
List the electrical characteristics that can be measured using a multimeter.
Definition
AC volts, DC volts, current, resistance and frequency in some meters
Term
How is the position of the decimal on the display changed?
Definition
By changing the range of the multimeter
Term
Explain the HOLD function on the fluke multimeter.
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
Term
How should the leads be connected to a circuit?
Definition
Common (black) first and positive (red) second
Supporting users have an ad free experience!