Chapter 7 - Airframe Electrical Systems - Oral Questions Flashcards Preview

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Flashcards in Chapter 7 - Airframe Electrical Systems - Oral Questions Deck (23)
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1
Q

What could cause an AC motor to run too fast?

A

Excessive applied voltage or shorted field windings

2
Q

What tool is used to check a motor or generator armature for shorts and opens under load conditions?

A

Growler

3
Q

When using a growler, what indication will occur when a short exists between an armature segment?

A

When a metal blade is held over the armature and a short exists in a segment, the blade will begin to vibrate and “chatter”.

4
Q

How is the output voltage of an alternator controlled?

A

By varying the field current that excites the alternator

5
Q

What instruments are used to monitor electrical system loads?

A

Ammeters and voltmeters

6
Q

How would you identify a specific wire in a wire bundle?

A

By the identification code marked on the wire

7
Q

What tool would you use to determine the size of an unmarked wire?

A

A wire guage

8
Q

What color are the navigation lights on the wingtips?

A

left is red, right is green

Right is spelled with 5 letters

Green is spelled with 5 letters

9
Q

Name several types of electrical devices that would be considered intermittent loads on an electrical system

A

Landing gear, cowl and wing flap motors, radio transmitters

10
Q

Why would it be necessary to analyze an electrical system before increasing the load on the system?

A

To determine that the generator capacity, wire size, and protective device capacity will not be exceeded

11
Q

What factors should be considered when determining the wire size for a particular application?

A

The system voltage,

permissible voltage drop,

current to be carried,

wire length,

and whether the load is continuous or intermittent

12
Q

What is the relationship between the inside diameter of a conduit and the outside diameter of the wire bundle inside it?

A

The conduit must be 25% larger than the wire bundle

13
Q

What is the maximum number of terminal lugs that can be placed on a single terminal strip stud?

A

Four

14
Q

What is the proper length for a bonding jumper?

A

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.

15
Q

Under what conditions must a switch be derated from its nominal rating?

A

When used with inductive circuits, circuits with high in-rush current, and with DC motors

16
Q

At what point do electric motors draw the most current?

A

When starting

17
Q

Circuit breakers are designed to open before what condition occurs?

A

Before the wire emits smoke

18
Q

At what point in a circuit should the protective device be located?

A

As close as possible to the power source

19
Q

What type of circuit breaker may not be used in an aircraft?

A

Automatic resetting type

20
Q

What part of an aircraft is identified by a white navigation light?

A

The Tail

21
Q

What could cause an AC electric motor to run too slowly?

A

Lack of lubrication, defective wiring, or low applied voltage

22
Q

What should be done when making bonding or grounding connections between dissimilar materials?

A

Use a suitable washer so that any corrosion will occur on the washer

23
Q

Prior to making a continuity check, what must be done to an electrical circuit?

A

The power must be turned off