Jeppensen Section D Flashcards
1
Q
- Two advantages of alternating current over direct current are
(A)
(B)
A
It is easy to generate
It is easy to change voltage and current values
2
Q
- The waveform of alternating current produced by a rotating generator is called a _____
Wave
A
Sine
3
Q
A
4
Q
- A _____ is one complete sequence of voltage or current changes from zero to a positive peak to zero then through a negative peak, and back to zero.
A
Cycle
5
Q
- An_______ is one-half of an AC cycle.
A
Alternation
6
Q
- The time required for one cycle of events to occur is known as the ______ of alternating
current.
A
Period
7
Q
- The number of complete cycles per second is the ______ of AC and is expressed in
________.
A
Frequency
Hertz
8
Q
- The AC power used in most aircraft is ______ hertz.
A
400
9
Q
- A rotating generator having four poles and turning at 1.800 rpm will generate an AC with a frequency of _____ hertz.
A
60
10
Q
- In an AC circuit the product of the voltage and the current is the ________ and is expressed in ________
A
Apparent power
Volt-amps
11
Q
- True power in an AC circuit is expressed in terms of _______ (watts or volt-amps).
A
Watts
12
Q
- The ratio between the true power and the apparent power in an AC circuit is known as the
___________
A
Power Factor
13
Q
- The maximum value of voltage in either the positive or negative direction is known as the ________ voltage.
A
Peak
14
Q
- The maximum difference between the positive and negative peak values of alternating voltage or current is called the _______ value.
A
Peak-to-Peak
15
Q
- The average value of alternating current is calculated by multiplying _______ by the peak value.
A
0.637
16
Q
The RMS value of AC is ________ times the peak value
A
0.707
17
Q
- Another name for the RMS value of AC is the ______ value
A
effective
18
Q
- A purely resistive circuit has a power factor of _________
A
One
19
Q
- Inductance opposes a change in current by the generation of a _______
A
Back Voltage
20
Q
- The amount of induction in a coil is affected by the
a.
b.
c.
d.
e.
A
Number of turns of wire
Spacing between the turns
Number of layers of winding
Ratio of the diameter of the coil to the length
Material used for the core
21
Q
- Increasing the inductance of a coil will _______ (increase or decrease) the amount of AC that can flow
A
Decrease
22
Q
- When inductors are connected in series, the total inductance can be found using what formula? __________
A
LT=L1+L2+L3+…
23
Q
- The total inductance is millihenries.
A
230
24
Q
- When inductors are connected in parallel. the total inductance can be found using what formula?
A
LT= 1/ (1/L1+1/L2+1/L3)
25
Q
A
26
Q
A
27
Q
A
28
Q
A
29
Q
A
30
Q
- The opposition to current flow in a conductor caused by the generation of a hack voltage as the magnetic field cuts across the conductor is called _________
A
Inductive Reactance
31
Q
31 Inductive reactance is indicated by the symbol _______.
A
X1
32
Q
- Inductive reactance is measured in ______.
A
Ohms
33
Q
- Inductive reactance ______ (increases or decreases) as the frequency increases.
A
Increases
34
Q
- Inductive reactance may be calculated using what formula?________
A
XL = 2pifL