ACM-105 (STUDY QUESTION) Flashcards
(310 cards)
1
Q
1 horsepower = ______ watts
A
746
2
Q
2 methods of charging battery
A
- Constant-current
- Constant-voltage
3
Q
A 60-watt light bulb installed in a 24-volt circuit will cause how much current to flow?
A
2.5 amps
4
Q
A 60-watt light bulb installed in a 24-volt circuit will cause how much current flow?
A
2.5 amps
5
Q
A battery converts ________ into _________
A
chemical energy
electrical energy
6
Q
A battery is a device which changes ______ energy to _______ energy
A
Chemical
Electrical
7
Q
A body having an accumulation of electrons on its surface is said to have a ____(positive or negative) static charge.
A
Negative
8
Q
A capacitor stores the _____ charge between 2 conductors separated by a dielectric (insulator)
A
electrostatic
9
Q
A capacitor used in an ac circuit should have a working voltage value of at least _____ greater than the applied voltage to reduce or eliminate the danger of the dielectric breaking down.
A
50%
10
Q
A capacitor’s ability to store an electrical charge is measured in _____. Most capacitors are measured in _____.
A
Farads
Microfarads
11
Q
A charged Atom is known as a(n) ____
A
Ion
12
Q
Using a soft iron core in an electromagnet increases its strength, those having _____ cores and those having _____ cores.
A
fixed
movable
13
Q
A hydrometer reading does not require a temperature correction at _____.
A
80° F
14
Q
A nickel-cadmium battery can maintain a nearly constant _____ (voltage or current) until it is almost totally discharged.
A
voltage
15
Q
A primary cell _______ be recharged.
A
Cannot
16
Q
A short occurs when _____
A
part of a circuit comes in direct contact with return side of the circuit.
17
Q
A trip-free circuit breaker means
A
once the breaker opens, the circuit remains open until the circuit cools regardless of position of the operating control.
Impossible to hold circuit closed if fault exists.
18
Q
According to the left-hand rule for electromagnets, the pole at end A of the electromagnet is the _____ pole.
A
North
19
Q
According to the left-hand rule, the lines of flux would encircle the conductor as shown in ____A or B?
A
B
20
Q
Aircraft wire is measured by the ____
The smallest wire normally used in aircraft is the ____ with a diameter of _____”.
A
American Wire Gage (AWG) system
22-gauge
0.25”
21
Q
An atom having fewer electrons than protons will carry a positive or negative charge.
A
Positive
22
Q
An atom having more electrons than protons will carry a positive or negative charge.
A
Negative
23
Q
An atom is made up of subatomic _____ called _____, _____, and _____.
A
particles
protons
neutrons
electrons
24
Q
An increase in inductance and frequency causes an _____ in inductive reactance.
A
increase
25
Batteries consisting of secondary cells are called ______
storage batteries
26
Both copper and aluminum exhibit _\_\_\_ changes in resistance with temperatures encountered in flight.
small
27
Both the positive and negative plates of a nickel-cadmium cell are made of powered nickel plaque, fused to a nickel screen.
A. The positive plates are impregnated with _____ hydroxide.
B. The negative plates are impregnated with _____ hydroxide.
Nickel
Cadmium
28
Capacitance is affected by 3 variables.
1. Area of storage plate
2. Separation between the plates
3. Composition of the dielectric (insulator)
29
Capacitors are divided into 2 types
1. Fixed
2. Variable
30
Capacitors are sometimes used in dc circuits to _____
smooth out slight pulsations in current / voltage.
31
Capacitors behave in series like resistors do in ______
parallel
32
Capacitors store energy 2 ways:
1. Through the electrostatic attraction across the dialectric.
2. Through the distortion of the electron orbits of the
33
capacity is measured in _______
ampere-hour
34
constant-current charging should be done at a rate of no more than _____ of the battery's ampere-hour rating.
7°
35
Copper wire has _\_\_\_ the resistance of an equivalent gauge of aluminum wire.
2/3
36
Define Alternating Current
Current that periodically changes direction and continuously changes in magnitude.
37
Define Effective Value of Alternating Current.
The direct current to produce an equal heating effect.
38
Define inductance
The transfer of electrical energy without electrical connections.
39
Define Instantaneous Value of Alternating Current.
Value of Voltage or current flowing in any instant.
40
Define Maximum Value of Alternating Current.
Maximum value of largest instantaneous value.
41
Define phase shift
42
Definition of capacity of a battery
ability to produce given amount of current for a specified time.
43
Definition of horsepower
Practical measure for power in electrical circuit
44
Definition of ohm's law
current that flows in a circuit is:
- directly proportional to the voltage (force) that causes it
- inversely proportional to the resistance (opposition).
45
Definition of Resistivity
The resistance of a standard length and cross-sectional area of a conductor.
46
Definition of specific gravity
ratio of the weight of a given volume of a material to the same volume of pure water.
47
Definition of ampere-hour
amount of electricity put into or taken from a battery when a current of 1 ampere flows for 1 hour.
48
Dielectric stress is expressed as ______
"K" value
49
Divide using powers of ten:
a. 326,000,000 / 1,900,000
b. 365,000 / 0.025
5,400 / 18
a. 1.72 x 10(2)
b. 1.46 x 10(7)
c. 3 x 10(2)
50
During the service of a nickel-cadmium battery, the electrical leakage between the cells and the case should be checked with a ______.
milliammeter
51
Each unit of electrical measurement may be expressed using a single letter. What letters are used for the expressions below?
1. Voltage
2. Current
3. Resistance
4. Power
1. E
2. I
3. R
4. P
52
How is electrical power expressed?
What is the symbol?
Watts
P
53
Electron flow is considered to be from the _\_\_\_ terminal of the battery (or other current source) through the circuit, and return to the _\_\_\_terminal of the battery.
Negative
Positive
54
Flexible metal braids called ____\_\_ straps connect the control surfaces to the aircraft structure to prevent the buildup of static charges.
Bonding
55
For applications requiring a great deal of current, _\_\_\_/ is used.
Why?
Aluminum wire
Aluminum weighs much less than copper
56
Formula for finding Current if Power and Resistance are known.
I = √P/R
57
Formula for finding Current if Power and Voltage are known.
I = P/E
58
Formula for finding Current if Voltage and Resistance are known.
I = E/R
59
Formula for finding Power if Resistance and Current are known.
E = IP and P = IE or P = I = I2R
60
Formula for finding Power if Voltage and Current are known.
P = IE
61
Formula for finding Power if Voltage and Resistance are known.
I = E/R and P = IE or P = E2/R
62
Formula for finding Resistance if Current and Power are known.
E = P/I and R = E/I or R = P/I2
63
Formula for finding Resistance if Power and Voltage are known.
I = P/E and R = E/I or R = E2/P
64
Formula for finding Resistance if Voltage and Current are known.
R = E/I
65
Formula for finding Voltage if Current and Resistance are known.
E = IR
66
Formula for finding Voltage if Power and Current are known.
E = P/I
67
Formula for finding Voltage if Resistance and Power are known.
E = √PR
68
Heat or burn on the hardware is an indication of _____
an indication of improperly torqued cell link connections
69
High charging currents in nickel-cadmium batteries may cause a breakdown of the cellophane-like cel separator material, resulting in a condition known as _____ or _____.
vicious
thermal runaway
70
High temperatures in a NICAD batteries cause the separating material inside the cells to break down which reduces the _____ _____ allowing more current flow causing more heat.
This process is called ______
internal resistance
thermal runaway
71
How are batteries rated?
according to voltage and ampere hour capacity.
72
How can the state-of-charge of a Nicad battery be determined?
By a measured discharge
73
How do you connect a voltmeter to test a circuit?
1. Connect it parallel to the circuit
2. Verify the polarity of the voltmeter is correct.
74
How do you determine the state of charge on a NICAD battery?
by a measured discharge
75
How do you use an ohm meter to correctly test for resistance?
1. Put ohm meter parallel to the resistance.
2. Must have 1 end of the circuit open
76
How is aircraft wire measured?
American Wire Gauge (AWG)
Larger numbers represent smaller wire size.
77
how is sediment buildup that can cause a short circuit prevented.
a space is placed under the plates.
78
How is the ratio between the resistance of a conductor and the cross-sectional area?
It varies inversely. As conductor's cross-sectional area increases, resistance increases.
79
How many watts = 1 horsepower
746
80
How much current is required for a 12-volt DC electric motor to produce 1/4 horsepower if we assume that there are no losses in the system?
1/4 horsepower = _\_\_\_ watts
In a 12-volt motor this will require _\_\_\_ amps
186.5 watts
15.54 amps
81
If 3 amps of current are flowing in a 12-volt circuit, how much resistance is present?
4 ohms
82
If 3 amps of current are flowing in a 12v circuit, how much resistance is present?
4 ohms
83
If an ammeter show a full charge rate, but the battery remains discharged what is the likely cause?
an internally shorted battery
84
If each cell, connected in series, equals 2 volts, how would a 12-cell lead-acid battery be rated?
24 volts
85
If electrolyte from a lead-acid battery is spilled in the battery compartment, which procedure should be followed?
apply sodium bicarbonate solution to the affected area followed by a water rinse.
86
If the capacity of a nickel-cadmium battery is less than it should be or if there is an indication that some of the cells are unbalanced, the battery should be _______.
deep cycled
87
If water is added to any cell of a nickel-cadmium battery, the amount and location of the cell should be recorded in the ______.
Battery Service Record
88
In a functional and operating circuit, the depicted logic gate's output will be 0.
1. Only when all inputs are 0.
2. When all inputs are 1
3. When one or more inputs are 0.
3
89
In Nicad batteries, a rise in cell temperature
causes a decrease in internal resistance
90
In the constant-voltage method of charging the amount of current that flows into a battery is determined by the battery's ________.
state of charge
91
In which circuits would aluminum wire be used?
Why?
Applications requiring a great deal of current.
Aluminum weighs much less than copper
92
What are materials which oppose the movement of electrons called?
Insulators
93
Materials which permit the flow of electrons are referred to as ________.
Conductors
94
Metals have a _______ meaning the resistance of the material ______ as its temperature increases.
positive temperature coefficient of resistance
increases
95
Most aircraft circuits use either _\_\_ or _\_\_ conductors.
1. Copper
2. Aluminum
96
Most aircraft electrical systems are of the _\_\_\_ type, meaning aircraft structure provides _\_\_\_\_.
Why?
single-wire type
the path through which current returns to the source.
Saves a lot of weight.
97
MULTIPLIER. PREFIX. SYMBOL
1,000,000 _____ _____
1,000
100
.001
0.000,001
0,000,000,001
0,000,000,000,001
MULTIPLIER. PREFIX. SYMBOL
1,000,000 Mega M
1,000. Kilo k
100 hecto h
.001 milli m
0.000,001. micro (mu)
0,000,000,001 nano n
0,000,000,000,001 pico p
98
Multiply and express your answers in scientific notation:
a. 325,000,000 x 1,500,000
b. 0.000,002 x 45
c. 750 x 0.25
a. 4.875 x 10(14)
b. 9 x 10 (-5)
c. 1.875 x 10(2)
99
Name 5 ways electrical energy may be generated.
1. Magnetism
2. Chemical
3. Thermal
4. Pressure
5. Light
100
Name 5 ways electrical energy may be generated:
1. Magnetism
2. Chemical
3. Thermal
4. Pressure
5. Light
101
NICAD batteries have _____ internal resistance allowing a high rate of charging current
low
102
Nicad batteries which are stored for a long period of time will show a low liquid level because ______
electrolyte becomes absorbed in the plates
103
Nicad batteries which are stored for long period of time will show ______ fluid level
low
104
NICAD battery cases and drain surfaces which have been affected by electrolyte should be neutralized with _____
boric acid
105
Nicad battery cases and drain surfaces which have been affected by electrolyte should be neutralized with a solution of _____
boric acid
106
Nickel-cadmium battery installations are required to have _____ monitoring equipment.
temperature
107
One volt results in the flow of 1 _\_\_\_?
Amp
108
One ____ is equal to a magnetic flux density of one weber per m2
Tesla
109
One _____ represents a magnetic flux density of one maxwell per square centimeter.
Gauss
110
overloading a circuit results from _____
loads that are too large for the wiring
111
Protective devices (circuit breakers / fuses) prevent damage caused by ______ resulting in large amounts of ______ or a _____ resulting in _____.
overloading
current flow
short
conductor heating
112
Resistor color codes:
First band - _____
Second Band - _____
Third Band - _____
Fourth Band - _____
No 4th band color - _____
1. First figure
2. 2nd figure
3. multiplier
4. tolerance
5. 20% tolerance
113
Specific gravity compares the density of 2 substances:
_____ is the standard for comparison for liquids and solids.
_____ is the standard for gases.
_____ of a liquid is measured with a hydrometer.
Water
Air
Specific Gravity
114
Spilled electrolyte can be neutralized with _____
sodium bicaronate and rinse with water
115
Spilled electrolyte from a lead-acid battery may be neutralized using a solution of ______ and water.
baking soda
116
State of charge determines ____________.....
current which will flow through a battery while being charged by a constant voltage source.
117
Static dischargers on an aircraft control surface provide sharp points from which a static charge can be dissipated from the control surface into the ________.
Air
118
The 2 most common switches used in aircraft are:
1. Enclosed toggle switch
2. Rocker switch
119
The active material on the negative plate of a fully charged lead-acid battery is ______
Spongy lead
120
The active material on the positive plate of a fully charged lead-acid battery is
Lead Peroxide
121
The ampere-hour capacity of a lead-acid battery is determined by what 4 things?
1. Amount of active material
2. Area of plates
3. Amount of electrolytes
4. Temperature
122
The battery ______ gives a good indication of the battery's charge.
specific gravity
123
The capacity of a battery is its ability to produce a given amount of _____ (voltage or current) for a specified time.
current
124
The constant ______ (current or voltage) charging method is the most effective method for charging aircraft batteries.
current
125
The ease with which lines of magnetic flux can pass through a material is known as a material's _\_\_\_.
Permeability
126
The electrolyte for a nickel-cadmium battery is __________ and water.
potassium hydroxide
127
The electrolyte level of a nickel-cadmium battery is ______ immediately after the battery is charged.
highest
128
The electrolyte of a lead-acid battery is made up of _____ _____ and water.
Sulfuric acid
129
The electrolyte of a nickel-cadmium battery is highest when the battery is _____
in fully charged condition
130
The end of charge voltage of a 19-cell nickel-cadmium battery, measured while still on a charge ______
depends upon its temperature and the method used for charging
131
The five-minute discharge rate of a lead-acid battery gives _____ (more or less) ampere-hours than the five-hour rate?
less
132
The generating system in an aircraft utilizes the constant _____ (voltage or current) method to charge a battery.
voltage
133
the lines of magnetic flux are considered to leave the _____ (north or south) pole of a magnet and enter at the ________ pole.
North
South
134
The method used to rapidly charge a nickel-cadmium battery utilizes _____
constant voltage and varying current
135
The most common used storage battery in light aircraft is the _________ battery.
Lead-acid
136
The open circuit voltage of a lead-acid battery is approximately _____ volts.
2.1
137
The open-circuit voltage of a lead-acid battery is _____
2.1 volts per cell
138
The presence of small amounts of potassium carbonate deposits on the top of nickel-cadmium battery cells that have been in service for a time is an indication of _____
normal operation
139
The purpose of a conductor is to _\_\_\_
provide a path for electrons to flow from a source through the load and back with minimum resistance.
140
The purpose of providing a space underneath the plates in a lead-acid battery's cell is to _______
prevent sediment buildup from contacting the plates and causing a short circuit.
141
The resistance of a conductor, the _\_\_\_ varies _\_\_\_ with the conductor's length.
The resistance of a conductor varies _\_\_\_ with it's cross-sectional area.
amount of resistance
directly
inversly
142
The resistance of a conductor is affected by 3 things:
1. Physical characteristics
2. Dimensions
3. Temperature
143
The resistance of a conductor is affected by 3 things: _\_\_\_
1. Physical characteristics
2. Dimensions
3. Temperature
144
The specific gravity of a fully charged lead-acid battery is approximately ______.
1.275
145
The specific gravity of the electrolyte in a nickel-cadmium battery _____ change as the state of the battery changes.
does not
146
The speed of electron movement is considered to be how many miles per second?
This is the same as the speed of what?
186,000
light
147
The strength of an electromagnet is determined by the _\_\_ and by the _____ flowing through it.
Number of turns
Amount of current
148
What is the unit of electrical pressure known as?
Volt
149
The voltage of batteries in parallel _____
remains the same
150
The voltage of batteries in series is _____
added
151
The white powder that forms on the top of a nickel-cadmium battery that has been in service is _______.
potassium carbonate
152
What is the standard unit of electrical resistance, or opposition to current flow.
What is the symbol?
Ohm
R
153
The _\_\_ is the basic unit of electrical charge (quantity) and is equal to 6.28 billion, billion electrons.
Coulumb
154
The _____ the dielectric stress the _____ the insulator's capacity
Higher
Greater
155
There are 2 types of electromagnets used in practical applications, those having _\_\_\_ cores and those having _\_\_\_ cores.
fixed
movable
156
Using a soft iron core in an electromagnet increases its strength because it is _\_\_\_ the lines of flux.
concentrates
157
What 3 things affect the resistance of a conductor?
1. Physical characteristics
2. Dimensions
3. Temperature
158
What 3 things do you need to create a light?
1. Power Source
2. Conductor
3. Source
159
What are photoconductive cells?
Variable resistor that is sensitive to light (Backlighting based on ambient brightness.
160
What are the 3 elements of a circuit?
1. Source
2. Load
3. Conductor
161
What are the 5 sources of electricity?
1. Chemical electricity - NICAD batteries
2. Thermocoupler - temperature difference causes current flow difference.
3. Light
4. Magnetrom
5. Electromagnetism
162
What are the disadvantages of a constant voltage method?
1. High charging rate could cause the battery to overheat.
163
What are the methods of charging batteries?
1. Constant voltage - charging airborne
2. Constant current method
164
What best describes the contributing factors to thermal runaway in a Nicad battery installed in an aircraft?
1. Low internal resistance intensisified by high cell temperatures.
2. High current discharge / charge rate in a constant potential (voltage) charging system.
165
What condition is an indication of improperly torqued cell link connections of a nickel-cadmium battery?
Heat or burn marks on the hardware
166
What contributes to thermal runaway
1. Low internal resistance
2. High cell temperatures
3. High current discharge / charge rate
167
What determines the amount of current which will flow through a battery while it is being charged by a constant voltage source?
The state of charge of the battery
168
What determines the amount of electricity a capacitor can store?
1. Directly proportional to the plate area.
2. Inversely proportional to the distance between the plates.
169
What determines the voltage of a fully charged NICAD 19 cell battery?
depends on the temperature & method used for charging.
170
What do switches do?
Safely control the flow of electrons
171
What does a bonding strap do?
provides a low-resistance path between a control surface and the aircraft structure.
172
What is a potentiometer?
Resistor that varies voltage in a circuit (Volume control audio panel)
173
What is a rheostat?
Resistor that varies the amount of current flow. (Light dimmer switch)
174
What is a thermistor?
Resistor that varies based on temperature. (Fridge thermostate)
175
What does EMF stand for?
What is the the definition of EMF?
What is the symbol for EMF?
Electromotive Force
The force to drive 1 amp to flow through 1 ohm of resistance.
(E)
176
What factors affect capacitance?
1. Ability to store a charge - measured in farads
2. Distance between plates determines electrostatic field.
3. Composition of the dielectric
177
What happens if you service lead-acid batteries and NICAD batteries in the same service area?
Can result in contamination of both types of batteries because fumes are not compatible with each.
178
What is a circular mil?
standard measurement of a round conductor's cross-sectional area
179
What is a coulumb and it's symbol?
Basic Unit of electric quantity
(Q)
180
What is a diode?
One-way check valve
181
What is a double-pole switch used for?
To control more than 1 circuit.
182
What is a single-pole, single-throw (SPST) switch?
What is it used for?
Switch that controls only 1 circuit and has 2 connections and 2 positions, open and closed.
To turn something on or off.
183
What is a trip-free circuit breaker?
Once the breaker opens, the circuit remains open until the circuit cools regardless of the position of the operating control.
184
What is an Amp?
What is it's symbol?
What is it also called?
1 Coulumb
(I)
Current
185
What is an electrostatic field?
Also known as _____
When 2 objects in close vicinity have a different electrical charge.
dielectric field
186
What is an Ohm?
What is it's symbol?
Measure of resistance to flow.
Ω
187
What is Electron flow?
What is Conventional flow?
Negative to Positive
Positive to Negative
188
What is inductive reactance?
The opposition of a coil to the flow of alternating current.
189
What is Kirchhoff's Law
The sum of applied voltage and the sum of voltage drops in a closed circuit will = 0.
190
What is Ohm's Law?
The flow of electrons = current.
191
What is positive temperature coefficient of resistance in metals?
The resistance of the material increases as its temperature increases.
192
What is Resistivity?
Resistance of a standard length and cross-sectional area of a conductor.
193
What is the advantage of a constant current method of charging?
controls the charging rate
194
What is the advantage of a constant voltage method of charging?
Rapid charging rate
195
What is the average specific gravity of a fully charged battery?
1.275 - 1.300 at 80°F
196
What is the basis for transformer operations in the use of alternating current?
Mutual inductance
197
What is the correct way to connect an ammeter to test
1. The ammeter should be in series with the circuit
2. Avoid creating an unintended 2nd path for the current.
198
What is the definition of a watt?
The amount of power dissipated when 1 amp flows under force of 1 volt.
199
What is the difference between a primary cell in a battery and a secondary cell?
Primary cell - active material cannot be restored.
Secondary cell - electricity can restore active material to a charged condition.
200
What is the disadvantage of a constant current method of charging?
lower rate of charge
201
What is the electrolyte used in a nickel-cadmium battery?
potassium hydroxide
202
What is the formula to figure Current when Power and Voltage are known?
I = P/E
203
What is the formula to figure Current when Voltage and Resistance are known?
I = E/R
204
What is the formula to figure Power when Current and Resistance are known?
E = IP / P = IE
205
What is the formula to figure Power when Current and Voltage are known?
P = IE
206
What is the formula to figure Resistance when Current and Voltage are known?
R = E/I
207
What is the formula to figure Voltage when Current and Power are known?
E = P/I
208
What is the formula to figure Voltage when Current and Resistance are known?
E = IR
209
What is the likely result of servicing and charging nickel-cadmium and lead-acid batteries together in the same service are?
contamination of both types of batteries
210
What is the maximum permissible resistance for a bonding strap?
.03Ω
211
What is the maximum permissible resistance of a bonding strap?
.003 ohms
212
What is the most important law to electricity?
Ohm's Law
213
What is the most probably cause of excessive amount of potassium carbonate formation?
battery overcharging
214
What is the purpose of a bonding strap?
Provides a conductive path between two structures.
215
What is the purpose of a conductor?
To provide a path for electrons to flow from a source through the load and back to the source with minimal resistance.
216
What is the purpose of the ground symbol used in electrical circuit diagrams?
shows a return path for fault currents and allows the fuse or breaker to disconnect the circuit.
217
What is the ratio between resistance and length in a conductor?
varies directly. As length increases, its resistance increases.
218
What is the smallest size of wire normally used in an aircraft?
22-gauge
219
What is the symbol for a variable capacitor?
220
What is the symbol for Current?
What is the unit?
I
Ampere
221
What is the symbol for Electrical Charge?
What is the unit?
Q
Coulumb
222
What is the symbol for Electromotive force?
What is the unit?
E or V
Volt
223
What is the symbol for Power?
What is the unit?
P
Watt
224
What is the symbol for Resistance?
What is the unit?
R
Ohm
225
What is the total power and total current for a 12-volt aircraft system with the following equipment installed?
a. Navigation lights, 3 lights at 20 watts each = _\_\_\_ amps
b. Radio #1, 60 watts = _\_\_\_ amps
c. Radio #2, 30 watts = _\_\_\_ amps
d. Interior lights, 30 watts = _\_\_\_ amps
Total power = _\_\_\_ watts
Total current = _\_\_\_ amps
a. 5
b. 5
c. 2.5
d. 2.5
Total power = 180 watts
Total current = 15 amps
226
What may result if water is added to a nickel-cadmium battery when it is not fully charged?
excessive spewing is likely to occur during the charging cycle
227
What will happen to a nicad-battery if water is added when not fully charged?
spewing will occur during charging
228
When a 5 ohm resistance is placed in a 20-volt circuit, how much current will flow?
4 amps
229
When a 5 ohm resistance is placed in a 20-volt circuit, how much current will flow?
4 amps
230
When a charging current is applied to a nickel-cadmium battery, the cells emit gas only _____
towards the end of the charging cycle
231
When a lead-acid battery is discharged, the active material on both positive and negative plates is converted to _____ _____.
lead sulfate
232
When a lead-acid battery is fully charged, most of the sulfuric acid is in the _____ (plates / solution)
solution
233
When charging multiple batteries what applies to the constant voltage method?
1. Must be connected in parallel
2. Can be different capacity but must be same voltage
234
When charging multiple batteries what applies to the constant current method?
1. Must be connected in series
2. Can be different voltage but must be same capacity.
235
When do NICAD batteries tend to emit gas?
toward the end of the charging cycle
236
When do NICAD batteries tend to heat up?
when current moves either in to or out of them
237
When electrons flow in a conductor, they cause a(n) _____________\_\_\_to surround the conductor.
Magnetic field
238
When installing a battery in an aircraft, you should connect the _____ lead first.
239
When is the electrolyte of a nickel-cadmium battery lowest?
When discharged
240
When one coulomb of electrons flows past a point in one second, there is a current flow of one ________.
What is the symbol?
Ampere
I
241
When referring to an electrical circuit diagram, what point is considered to be at zero voltage?
ground reference
242
When removing a battery from an aircraft, you should remove the _____ lead first.
negative
243
Which shell determines whether you have a conductor or insulator?
Outer Shell
244
Why do turbine engines need Nicad batteries?
require an extremely high current for starting.
245
Why is copper wire generally used in aircraft circuits?
It has about 2/3 the resistance of aluminum wire of the same gauge.
246
With left-hand rule of thumb for coils. If you grasp the conductor in your left hand with your thumb point in the direction of electron flow, your thumb points to the ______________.
north pole
247
With left-hand rule of thumb for electron flow. If you grasp the conductor in your left hand with your thumb pointing in the direction of electron flow, your fingers encircle the conductor in the direction of the ______________.
lines of flux travel
248
Write the following numbers using metric prefixes:
a. 126,000,000 ohms
b. 0.002 amp
c. 156,000 volts
d. 0.000,000,000,003 farads
e. 115,900,000 hertz
f. 326,000 meters
a. 126
b. 2
c. 156
d. 2
e. 115.9
f. 326
249
____ is the ability of a material to retain magnetism after a magnetizing force is removed.
Retentivity
250
_____ have a much lower freezing point than water in batteries.
sulfuric acid
251
_____ is the magnetism remaining in a material after the magnetizing force has been removed.
Residual magnetism
252
What is the opposition to the flow of magnetic force.
Reluctance
253
8597
What schematic symbol represents a current limiter?
1. A triangle and a Z-like symbol across a horizontal line.
2. One triangle pointing to a vertical line.
3. Two triangles pointing to each other with a line on both sides of the triangles.
254
QUIZ
Define Short Circuit?
A low resistance path across a power source or between 2 points in a circuit.
255
QUIZ
Define Open Circuit
Circuit that is not continuous or complete.
256
QUIZ
Voltmeter is hooked in:
In parallel
257
QUIZ
An ammeter is hooked up in:
Series
258
QUIZ
What point in a circuit would you have 0 voltage?
After the load
259
QUIZ
How is the solenoid connected into the circuit?
Fig 3-213
Switch
In series
B terminal is hot
260
QUIZ
2 Problems with transformers 3-146.
1. Windings could be open - no voltage flows out of transformer to load.
2. Windings shorted
261
What is the result of an open circuit?
Broken conductor or damaged component.
Burned out bulb or fuse
262
What happens to resistance in a short circuit?
Circuit resistance decreases and current flow increases.
263
What is the result of a short circuit?
Increased flow can result in circuit over-heating and burning the conductor and circuit components
264
3-96 (1)
2 Advantages of AC current over DC:
1. Easier to generate in large quantities
2. Easier to change voltage and current values
265
3-96 (2)
The waveform of alternating current produced by a rotating generator is called a _____ wave.
sine
266
3-93 (3)
The current generated in the coil passing through a magnetic field is greatest at 0 degrees or 45 degrees?
45 degrees
267
3-96 (4)
A _____ is one complete sequence of voltage or current changes from 0 to a positive peak to 0, then through a negative peak, and back to 0.
Cycle
268
3-96 (5)
An _____ is 1/2 of an AC cycle
Alternation
269
3-96 (6)
The time required for 1 cycle of events to occur is known as the _____ of alternating current.
period
270
3-96 (7)
The number of complete cycles per second is the _____ of AC and is expressed in _____.
Frequency
Hertz
271
3-96 (8)
The AC power used in most aircraft is _____ hertz.
400
272
3-96 (9)
A rotating generator having 4 poles and turning at 1800 rpm will generate an AC with a frequency of _____ hertz.
60
273
3-96 (10)
In an AC circuit the product of the voltage and the current is the _____ _____ and is expressed in _____.
Electrical power
Watts
274
3-96 (11)
True power in an AC circuit is expressed in terms of _____.
watts
275
3-96 (12)
The ratio between the true power and the apparent power in an AC circuit is known as the _____.
Power factor
276
3-96 (13)
The maximum value of voltage in either the positive or negative direction is known as the _____.
Peak
277
3-96 (14)
The maximum difference between the positive and negative peak values of alternating voltage or current is called the _____ value.
Peak to power
278
3-96 (15)
The average value of alternating current is calculated by multiplying _____ by the peak value.
.637
279
3-97 (16)
The RMS value of AC is _____ times the peak value.
.707
280
3-97 (17)
Another name for the RMs value of AC is the _____ value.
Effective
281
3-97 (18)
A purely resistive circuit has a power factor of _____.
1
282
3-97 (19)
Inductance opposes a change in current by the generation of a _____.
Back voltage
283
3-97 (20)
The amount of induction in a coil is affected by the:
A. Number of turns of wire
B. Spacing between turns
C. Number of layers of winding
D. Ratio of diameter of coil to the length
E. Material used for coil
284
3-97 (21)
Increasing the inductance of a coil will _____ the amount of AC that can flow through it.
decrease
285
3-97 (22)
When inductors are connected in series, the total inductance can be found using what formula?
Lt = L1 + L2 + L3
286
3-97 (23)
The total inductance is: Screenshot pg 3-97
287
What are the smallest particles that can exist, either alone or in combination?
Atoms
Atoms are the fundamental building blocks of matter.
288
What are the two types of particles found in the nucleus of an atom?
Protons and neutrons
Protons are positively charged, and neutrons are neutrally charged.
289
What charge do electrons carry?
Negatively charged
Electrons are essential in determining the chemical properties of atoms.
290
How much does an electron weigh compared to a proton?
1/1845 as much
This significant difference in mass makes protons and neutrons the primary contributors to atomic mass.
291
What determines the material that atoms make up?
The number and arrangement of protons, neutrons, and electrons
This arrangement influences the chemical properties and behavior of the element.
292
How many protons are in the nucleus of a copper atom?
29 protons
The number of protons defines the element as copper.
293
How many neutrons can be found in a copper nucleus?
34 or 36 neutrons
The variation in neutrons leads to different isotopes of copper.
294
How many electrons surround the nucleus of a copper atom?
29 electrons
An electrically balanced atom has equal numbers of protons and electrons.
295
What is an electrically balanced atom?
An atom with the same number of positive charges as negative charges
This balance means that the atom has no overall electrical charge.
296
What role do neutrons play in the flow of electricity?
They do not affect the flow of electricity
Neutrons are neutral and do not contribute to electrical charge.
297
Fill in the blank: Atoms consist of a nucleus containing _______ charged protons and _______ charged neutrons.
positively; neutrally
This is a fundamental aspect of atomic structure.
298
What is the structure surrounding the nucleus where electrons are found?
Shells
Electrons occupy different energy levels or shells around the nucleus.
299
What is the composition of the nucleus of a copper atom?
29 positively charged protons and 36 electrically neutral neutrons
The nucleus contains protons and neutrons, which are fundamental particles of the atom.
300
How many negatively charged electrons are present in a copper atom?
29 negatively charged electrons
The number of electrons is equal to the number of protons in a neutral atom.
301
What is the condition for an atom to be electrically balanced?
The positive charges equal the number of negative charges
This balance is essential for the stability of the atom.
302
What causes the electrons to spin around the nucleus?
Energy in an atom
All matter contains energy, which affects atomic structure.
303
What force opposes the centrifugal force pulling electrons away from the nucleus?
Electrostatic attraction between protons and electrons
This force is crucial for maintaining electron orbits.
304
What are the shells in which electrons spin around the nucleus?
Shells at a constant radius
Electrons occupy specific energy levels or shells around the nucleus.
305
How many shells can some atoms have?
Up to seven shells
The number of shells depends on the number of electrons in an atom.
306
How many electrons can the first shell hold?
2 electrons
## Footnote
The capacity of each shell increases with distance from the nucleus.
307
How many electrons can the second shell hold?
8 electrons
The second shell is filled after the first shell is complete.
308
How many electrons can the third shell hold?
18 electrons
This shell can hold more electrons due to its larger energy level.
309
What is the outermost shell of an atom called?
Valence shell
The valence shell contains the electrons that participate in chemical bonding.
310
What are the electrons in the valence shell referred to as?
Valence electrons
Valence electrons determine an atom's chemical properties.
