ESI Level 1 DC Circuits Study Guide Flashcards
1
Q
Ohm’s law; Solve for: E
A
E=I * R
E= P/I
E= square root of “P*R
2
Q
Ohm’s law; Solve for: R
A
R= E/I
R= E”squared” / P
R = P/I “squared”
3
Q
Ohm’s law; Solve for: I
A
I=E/R
I=P/E
I=square root of “P/R”
4
Q
Ohm’s law; Solve for: P
A
P=EI
P=I”Squared”R
P=E”squared” /R
5
Q
Atomic theory
A
Parts of the Atom
6
Q
Parts of the Atom
A
Protons
Electrons
Neutrons
7
Q
Protons are
A
Positive
8
Q
Electrons are
A
Negative
9
Q
Neutrons are
A
No charge
10
Q
Electrons ________ the nucleus in ________.
A
Orbit
Shells
11
Q
The outter-most shell of a nucleus is the
A
Valence shell
12
Q
Electrons in the valence shell are called
A
Valence electrons
Free electrons
13
Q
Conductors have many
A
Free electrons
14
Q
Insulators have
A
Few free electrons
15
Q
All atoms want to be
A
Stable with the same number of positive (protons) and negative(electrons)
16
Q
Unstable atoms are called
A
Ions
17
Q
Ions can be
A
Positive and negative
18
Q
Conductors have
A
1,2 or 3 valence electrons
19
Q
Insulators have
A
5,6,7 or 8 valence electrons
20
Q
Semi-conductors have
A
Exactly 4 valence electrons
21
Q
Methods of creating voltage
A
Chemical
Heat
Friction
Magnetism
Pressure
Light
22
Q
Multi-meter (analog meter): 4 things
A
-Low input resistance
-scalable
-uses D’arsonval movement
-mirror to overcome parallax error
23
Q
4 things about multi-meter Digital meter (DMM)
A
-high input resistance
-greater accuracy
-LCD display
-Diverse functions
24
Q
When using a multi-meter to measure voltage
A
Place meter in parallel across the component to be measured (power on)
25
When using a multi-meter to measure resistance
Place the meter in parallel across the component to be measured (power off)
26
When using a multi-meter to measure current
-create an “open” in the circuit to be measured
-place the meter in series with the circuit (power on)
27
Continuity defined
A little to no resistance path between two points aka continuous
28
Metric prefixes:mili
10 squared -3
29
Metric prefixes: micro
10 squared -6
30
Metric prefixes: nano
10 squared -9
31
Metric prefixes: Pico
10 squared -12
32
Metric prefixes: kilo
10 squared 3
33
Metric prefixes: mega
10 squared 6
34
Metric prefixes: giga
10 squared 9
35
Metric prefixes: tera
10 squared 12
36
Magnetism terms:
Permeability
Retentivity
Temporary magnet
Permanent magnet
37
Metric prefixes: permeability
Easily magnetized
38
Metric prefixes: retentivity
Retains magnetism
39
Metric prefixes: temporary magnet
Sometimes magnetized
40
Metric prefixes: permanent magnet
always magnetized
41
To eliminate shock potential when working on AC powered equipment:
Use an isolation transformer
42
To protect circuits and equipment from excess current use
-an inline fuse or
-GFI-ground fault interrupter
43
Never provide an electrical pathway
Through your body to ground
44
The human body is an excellent
Conductor
45
Resistance defined
The opposition to flow of current in a circuit
46
Types of resistors
General purpose
Power
Precision
47
General purpose resistors
Carbon film
Carbon composite
48
All carbon resistors have
Color bands identifying their value
49
Power resistors
Wire wound
Used for High current and High heat
50
Precision resistors
Metal film
Tight tolerances
51
Resistors are measured in
Ohms and watts
52
Resistor color code
Black-0
Brown-1
Red-2
Orange-3
Yellow-4
Green-5
Blue-6
Purple-7
Grey-8
White-9
53
Resistor color band tolerance
Gold +/- 5%
Silver +/- 10%
None +/- 20%
54
Resistor 3rd band color for multipliers
3rd band gold *.1
3rd band silver *.01
55
EMF
Electromotive force
56
CEMF
Counter electromotive force
57
ESD
Electro static discharge
58
Static sensitive: integrated circuits IC use
Wrist or ankle ground strap
59
Draw ESD (don’t touch unless grounded) sign
Triangle w/ hand and line through it
60
Draw high voltage sign
Yellow triangle w/ squiggly arrow pointed south
61
Resistor aka
Dummy load
62
Resistor symbol
Squiggly line
63
Variable resistor types
Potentiometer
Rheostat
64
Variable resistor symbol
Squiggly line with arrow pointed at it
65
Chassis ground symbol
Draw
66
Earth ground symbol
Draw
67
Ground is
The reference point for circuit measurements
68
Batteries in series
Increased voltage
Current stays the same
69
Batteries in parallel
Increased current
Voltage stays the same
70
Stranded wire ends must be
Tinned
71
Never use ________ _________ on electronics
Acid flux
72
To remove solder use
Solder wick
73
Current flows from
Negative to positive
74
Current seeks
The path of least resistance
75
Series circuits have __________ pathway for current flow
One
76
Total resistance in a series circuit is
The sum of the individual resistors
R(T)=R(1)+R(2)+R(3)……….
77
The total current I(T) is the _________ throughout a series circuit
Same
78
The voltage applied throughout a series circuit is _______ among the resistors (_______) in the circuit
Divided
Loads
79
In a series circuit the sum of the voltage divisions (_________) must equal the _________ __________
Drops
Applied voltage
80
In a series circuit What happens when a component is shorted?
It removes only the shorted component from the circuit
81
In a series circuit What happens to the resistance?
The total resistance decreases
82
In a series circuit What happens to the current.
The total current flow increases
83
In a series circuit when a component shorts What will the ohms and voltage drop measure?
Zero ohms
Zero voltage drop
84
When a series circuit has a shorted component What happens to the applied voltage?
The applied voltage is still divided among the remaining components
85
Open component in a series circuit does what to the current?
Nullifies the current to zero
86
What happens to the total resistance when there’s an Open component in a series circuit
Total resistance increases to infinity
87
What happens to the one “Open” component in a series circuit
The opened component measures infinity ohms
88
Open component in a series circuit the voltage dropped across to open component will measure
The applied voltage
89
Attributes of a short in a series circuit
Excessive heat
Excessive current blows fuse/breaker
Low to no resistance
90
Attributes of an open component in a series circuit
No current flow
Infinite resistance
91
Parallel circuits provide ______ ________ ________ pathways for current flow
2 or more
92
In parallel circuits the applied voltage is
The same throughout the circuit
93
In a parallel circuit the current flow will be
Divided among the individual “branches” of the circuit
94
The sum of the individual branch currents must be
Equal to the total current
95
Total resistance in a parallel circuit can be determined by;
Write out 3 different ways
96
In a Parallel circuit a shorted component will (current)
Increase the circuit current to maximum (current takes the path of least resistance
97
In a Parallel circuit a shorted component will (resistance)
Total resistance is reduced to zero
98
In a Parallel circuit a shorted component will (voltage)
Voltage across the shorted component is zero volts
99
In a Parallel circuit a shorted component E will equal
Zero
100
In a Parallel circuit an open component will (current)
No current flows through the open branch
101
In a Parallel circuit an open component will (resistance)
The total resistance increases
102
In a Parallel circuit an open components will (current)
The total current decreases
103
In a Parallel circuit an open component resistance measures
Infinity
