notes Flashcards
(111 cards)
1
Q
Matter is composed of?
A
Atoms
2
Q
Atoms are broken up into even smaller particles which are?
A
subatomic particles
3
Q
what are the smallest particles that elements can be broken into and still retain properties of the element?
A
Atoms
4
Q
Two subatomic particles are found within the nucleas?
A
Protons and neutrons
5
Q
What is the heaviest part of the atom?
A
Nucleas
6
Q
What is the third subatomic particles?
A
electrons
7
Q
What does electrons do?
A
They are in motion around the nucleus and have negative charge.
8
Q
Electrons occupy various energy levels around the nucleus known as?
A
Shells
9
Q
The outer shell of the nucleus is called?
A
Valence shell
10
Q
The number electrons that reside in the valence shell is determined by?
A
Conductors, Semiconductors and insulator.
11
Q
Valence shells holds a maximum of?
A
Eight electrons
12
Q
What is an insulator?
A
something through electricity cannot pass
13
Q
What is a semiconductor?
A
a material that conducts current.
14
Q
What is current?
A
flow of electricity through a conductor
15
Q
Current is measured in?
A
Amperes
16
Q
Ampere is defined as?
A
One Coulomb
17
Q
The symbol used for amps is?
A
A
18
Q
What is the basic unit of electrical charge?
A
Coulomb
19
Q
What is current measured with?
A
Anmeter
20
Q
What is pressure to an electron?
A
electromagnetic repulsion from a larger negative charge
21
Q
What is electrical pressure measured in?
A
Volts
22
Q
What is voltage also known for?
A
electrical potential difference & electromotive force
23
Q
You measure volts with?
A
Voltmeter
24
Q
What is resistance?
A
hinders of electric flow
25
Resistance is measured in?
Ohms
26
How is one ohm defined?
The amount of resistance that will allow one ampere of current to flow if one volt of electrical pressure is placed on a conductor
27
Resistance can be measured by?
a ohmeter
28
Current and resistance are?
inverserly proportional
29
Voltage and current are?
Directly proportional
30
What are the three most common things used as conductors?
Silver, copper and aluminium
31
What is the most expensive conductor?
Silver
32
What is conventional current?
flow of positive charge and is opposite in direction to actual electron flow.
33
What is a circuit?
A complete loop or path that electricity can follow
34
What are three essential components of an electrical circuit?
Voltage Source, Load, Conductors
35
What is a closed circuit?
Current can flow in an uninterrupted path
36
What is a load?
converts one type of electricity to another
37
What is a open circuit?
A circuit that is not complete
38
The relationship between voltage, current and resistance through a wire is called?
Ohms Law
39
What is the formula of Ohms Law?
V=IR
40
What does the I stand for in Ohms Law?
Current
41
What is a example of voltage source?
Batteries
42
What is a series circuit?
A circuit that has only one path for current to flow
43
What is a parallel circuit
voltage is the same throughout each parallel branch of the circuit, while current flow varies.
44
Most residential circuits are what kind?
Series-parallel
45
What is electrical power?
the actual rate at which energy is provided to and consumed by a electric circuit
46
What is power expressed in?
Watts
47
what is the power law equation?
P=IV
48
What is electricity?
flow of electrons through a conductor such as copper or aluminium wire
49
What is a conductor?
material through which electricity can pass
50
What is voltage?
strength which with current flows through a conductor
51
what is power?
The amount of energy transferred through a specify time
52
What is watts?
measure of electric power
53
Most things in your house requires how many volts?
120
54
What do you use to measure watts?
watt meter
55
What does AC Current stand for?
Alternating Current
56
What does DC Current stand for?
Directing Current
57
What direction does AC Current flow?
both direction
58
What direction does DC Current flow?
in one direction
59
A circiuit is?
A sys of connected conductors that direct the path of electricity.
60
What is a resistor?
Resists the flow of current and can change the amount of current that's flowing through.
61
What is the diode?
allows electrical current to flow only in one direction
62
What is frequency?
A measurement of how many times a certain thing is done in a certain amount of time
63
What is frequency expressed in?
Hertz
64
What are waves measured in?
Wave lengths
65
What are some examples that work on DC?
Cell Phones, laptops, and electronic devices
66
What is a AC Current?
current that changes direction many times in a second as it moves in a conductor
67
What are some items that deliver AC Current?
HHousehold electrical outlets
68
How many hertz is AC delivered in?
60 hertz
69
What is hertz?
the frequency of the signal and how many complete cycles occur in 1 second.
70
What is the frequency equation?
f= 1/T
71
What is ground?
the lowest potential in a circuit
72
What wiring is common in residential wiring?
Ground Wiring to prevent electric shock
73
What is a resistor do?
A component used to limit current or voltage
74
What are the two types of resistors?
Fixed and variable.
75
What is a fixed resistor
fixed resistance
76
What is a variable resistor?
resistances that can be changed
77
What are potientiometers good for?
changing the voltage drop across a component in a circuit
78
What can potientionmeters good for?
adjusting the volume in a tv radio or stereo
79
What are two types of variable resistors?
rheostats and potientionmeters
80
Fixed resistors use a certain system to help determine resistance in ohms what is this called?
Color Band System
81
Fuses and Circuit breakers are very important too?
Circuits
82
How does a short circuit occurs?
a load is bypassed with a conductor
83
What are fuses?
Thin wires that melts when current exceeds a prescribed amount and preventing electricity flowing
84
What is one disadvantage of a fuse?
When it is blown it has to be replaced before the circuit works again
85
What is one advantage a circuit breaker has over a fuse?
Able to be reused multiple times
86
What are capacitors?
are electrical storage units
87
How are capacitors constructed?
Two metal conduction plates with a very thin insulator
88
A capacitors opposition to flow of current is called?
A capacitive reactance
89
Capacitance is represented by what letter symbol?
C
90
What two materials joined together create diodes?
P types and N types
91
What is a transistor?
a semiconductor device with three connections
92
What are the two types of transistors?
NPN & PNP
93
What is a NPN Transistor made up of?
thin piece of p-type material sandwiched between two pieces
94
What is PNP transistor made up of?
two pieces of p-type material that have a N-type material between them
95
What is the middle piece in a transistor called?
base
96
What is the two outside pieces called?
Collector & Emitter
97
How does a PNP Transistor works?
requires negative volatge at the base to turn on. Then current flows from the emitter to the collector
98
A diode only outputs?
DC Current
99
What are the positive charges?
Protons
100
What are the negative charges?
Electrons
101
What are some examples of EM Waves?
Light, Radio & X-Ray Waves
102
All EM Waves travel through a vacuum at the speed of light?
186,000 mph
103
Current is denoted by?
I
104
What are the best conductors?
Silver and Copper
105
Silver & Germainium are great examples of?
Semiconductors
106
Poor Conductors are also known as?
Insulators
107
What is impedance?
Anything that effects the flow of current
108
What is a particular kind of impedence?
Resistance
109
Electromagnetic waves travel through?
A vacuum
110
What is C means?
Capacitor
111
What is a fuse?
A circuit element that allows the flow of current below a certain value.
