AS113-4 Course Review Flashcards
What is a battery?
A Device that convert chemical energy into electrical Energy
Name the two types of cells of a battery.
Primary cell Dry
Secondary cell Wet
What would the hydrometer reading be for a fully charge lead-acid battery? __________
1.275 or 1.3
During an installation of a battery into an aircraft, when should the negative terminal be connected?
Second after the positive lead
What is “deep cycling” or equalization of a battery?
Continue to discharge the battery but at a slower rate
When cells voltage gets to .2VDC per cell, short the cells with shorting strips
Leave straps on 3 to 8 hours
What will a measured discharge test tell the mechanic?
The state of the battery
Capacity of a Nickel Cadmium Battery
How do you check the state of charge for a lead-acid battery? _________________
Hydrometer
What happens to the electrolyte in a lead acid battery during discharge?
Dilutes
What is used to check specific gravity of a lead acid battery?
Hydrometer
How many volts per cell are in a NiCad battery?
1.5 to 1.8
How many volts per cell are in a lead acid battery?
2.1
What are two ratings found on aircraft batteries?
Voltage
Ampere Hour capacity rating
What is used to neutralize a NiCad battery’s electrolyte?
Boric Acid and Vinegar
What is used to neutralize a lead acid battery’s electrolyte?
Sodium Bicarbonate
If batteries are connected in parallel with each other, what increases?
Amps / Capacity
What is one complete sequence from zero to positive peak to zero, then to negative peak and back to zero?
Cycle
What is the definition of frequency?
of cycles in 1 sec, measured in Hz
What is another name for RMS Value?
Effective Value
What is the power factor of a purely resistive circuit?
1
What is the phase angle when current and voltage are in phase?
0
What is the power factor when current and voltage are in phase?
1
What is the power factor of a purely capacitive circuit?
0
What value does a meter read when measuring AC?
RMS
In an AC circuit, effective value is always (greater or less) than peak?
Less
True power will never be (greater or less) than apparent power?
Greater
Looking at the frequency formula, what factors affect output frequency? _
of poles and RPM
An inductor is defined as:
A coil of wire.
Changes the values of alternating current and voltage
What letter is used to represent inductance?
L
What four factors affect the inductance of a coil?
Type of core
Size of wire
Number windings
Spacing and shape in coil
Inductive reactance is defined as:
The opposition to AC current flow that is caused by the presence of an inductor in the circuit
What does current do with respect to voltage in an inductive circuit?
Lags
What happens to inductive reactance if frequency is increased?
increases
Transformers work off of what electrical principle?
Mutual Inductance
If a transformer has a 10:1 turns ratio with an input of 28 volts and 1 amp, what will the output be?
2.8 V, 10 Amps
What type of transformer is in the question above?
Step Down
A capacitor is defined as:
A device used to store electrical energy in the form of electro static fields.
A capacitor is essentially two conductors separated by an insulator
How does a capacitor store electrical energy?
Electrostatic Fields
What letter is used to represent capacitance?
C
What three factors affect the capacitance of a capacitor?
Area of plates
Separation between plates
Composition of dielectric
What are two ratings found on capacitors?
Capacitance
Voltage
What does the working voltage of a capacitor have to be compared to the applied voltage?
50% higher than the highest voltage
What dielectric does a self healing capacitor have?
Oil
Capacitive reactance is defined as:
Opposition offered by a capacitor to the flow of alternating current though it
What does current do with respect to voltage in a capacitive circuit?
Leads
What happens to capacitive reactance if frequency is increased?
Decreases
Impedance is defined as:
measure of the opposition to electricity flow
What is the name of a device that changes AC into DC?
Rectifier
What happens when a capacitor is placed into a rectifier circuit?
Smooths out the voltage
Resonant frequency is defined as:
Frequency at which the inductive and capacitive reactance are the same
