Chapter 7 - Airframe Electrical Systems - Oral Questions Flashcards
What could cause an AC motor to run too fast?
Excessive applied voltage or shorted field windings
What tool is used to check a motor or generator armature for shorts and opens under load conditions?
Growler
When using a growler, what indication will occur when a short exists between an armature segment?
When a metal blade is held over the armature and a short exists in a segment, the blade will begin to vibrate and “chatter”.
How is the output voltage of an alternator controlled?
By varying the field current that excites the alternator
What instruments are used to monitor electrical system loads?
Ammeters and voltmeters
How would you identify a specific wire in a wire bundle?
By the identification code marked on the wire
What tool would you use to determine the size of an unmarked wire?
A wire guage
What color are the navigation lights on the wingtips?
left is red, right is green
Right is spelled with 5 letters
Green is spelled with 5 letters
Name several types of electrical devices that would be considered intermittent loads on an electrical system
Landing gear, cowl and wing flap motors, radio transmitters
Why would it be necessary to analyze an electrical system before increasing the load on the system?
To determine that the generator capacity, wire size, and protective device capacity will not be exceeded
What factors should be considered when determining the wire size for a particular application?
The system voltage,
permissible voltage drop,
current to be carried,
wire length,
and whether the load is continuous or intermittent
What is the relationship between the inside diameter of a conduit and the outside diameter of the wire bundle inside it?
The conduit must be 25% larger than the wire bundle
What is the maximum number of terminal lugs that can be placed on a single terminal strip stud?
Four
What is the proper length for a bonding jumper?
As short as practical, but long enough to allow free movement of the component
Bonding - The process of electrically connecting all isolated
components to the aircraft structure. Bonding provides a
path for return current from electrical components, and a
low-impedance path to ground to minimize static electrical
charges. Shock-mounted components have bonding braids
connected across the shock mounts.
Under what conditions must a switch be derated from its nominal rating?
When used with inductive circuits, circuits with high in-rush current, and with DC motors
At what point do electric motors draw the most current?
When starting
Circuit breakers are designed to open before what condition occurs?
Before the wire emits smoke
At what point in a circuit should the protective device be located?
As close as possible to the power source
What type of circuit breaker may not be used in an aircraft?
Automatic resetting type
What part of an aircraft is identified by a white navigation light?
The Tail
What could cause an AC electric motor to run too slowly?
Lack of lubrication, defective wiring, or low applied voltage
What should be done when making bonding or grounding connections between dissimilar materials?
Use a suitable washer so that any corrosion will occur on the washer
Prior to making a continuity check, what must be done to an electrical circuit?
The power must be turned off
