Science Exam Flashcards
(136 cards)
1
Q
a branch of the study of electricity that deals with the behavior and motion of electrons in a vacuum or in semiconductors
A
electronics
2
Q
negative electrode of a vacuum tube
A
cathode
3
Q
positive electrode of a vacuum tube
A
anode
4
Q
glass tube containing electrodes sealed in a vacuum
A
vacuum tube
5
Q
Early experimenters with vacuum tubes knew something was crossing the gap between electrodes in a vacuum, so they named them ______
A
cathode rays
6
Q
designed so that the cathode rays would miss the anode and strike the end of the glass tube instead
A
cathode-ray tube (Crookes tube)
7
Q
special type of vacuum tube to study cathode rays
A
cathode-ray tube (Crookes tube)
8
Q
cathode-ray tube designed to generate x-rays
A
x-ray tube
9
Q
tube designed to generate rays that were originally unknown
A
x-ray tube
10
Q
The production of an electric current in a vacuum using a heated cathode
A
thermionic emission (Edison effect)
11
Q
a vacuum tube in which current only flows one direction; has 2 electrodes
A
diode
12
Q
a simple vacuum tube consisting of two electrodes
A
diode
13
Q
a vacuum tube with three electrodes
A
triode
14
Q
_____ acts as a very fast electronic switch
A
triode
15
Q
a material that is neither a good conductor nor a good insulator
A
semiconductor
16
Q
process where you can increase the number of holes or electrons by replacing some of the atoms of the semiconductor with atoms of another element
A
doping
17
Q
material with extra electrons that are free to move
A
n-type semiconductor
18
Q
material with extra holes lacking negative charge
A
p-type semiconductor
19
Q
semiconductor device that, like a vacuum-tube diode, allows current to pass in only one direction
A
semiconductor diode
20
Q
True or false: a p-n junction allows current to flow in only one direction
A
true
21
Q
a semiconductor device that can perform the same functions as a vacuum-tube triode, such as acting as a “switch” and amplifying weak signals
A
transistor
22
Q
A semiconductor device that produces electric current through the separation of charges through light
A
photovoltaic cell
23
Q
devices that consist of solid crystals of semiconductor
A
solid-state devices
24
Q
the most common type of transistor used today
A
FET (field-effect transistor) - found in computer chips
25
semiconductor diode that emits visible light when an electric current is applied
LED
26
device consisting of a single piece of semiconductor containing an entire electronic circuit
integrated circuit (chip)
27
three benefits of integrated circuits
1. smaller
2. cheaper
3. more reliable
28
True or false: the effects of the transistor revolution are far greater than the effects of the integrated-circuit revolution.
false - it is the opposite
29
device that processes information using electronic circuits
computer
30
pieces of information
data
31
America’s first mass-produced computer
UNIVAC 1
32
first general-purpose electronic computer
ENIAC
33
The modern computer era is said to have begun with the completion of ______
ENIAC
34
random variations that affect any signal
noise
35
data that can have any possible value within a specified range
analog data
36
data that can have only certain values within a range
digital data
37
practically all modern electronic computers are _____ computers
digital
38
number system based on powers of 2
binary number system
39
number system based on powers of 16
hexadecimal number system
40
computer coding system upon which most other common coding systems are based
ASCII
41
a device that produces a single binary output based on one or more binary inputs
logic gate
42
the physical components of a computer
hardware
43
The “brain” of the computer; controls all the other systems of the computer, performs calculations, and executes the commands needed to accomplish specific tasks
CPU (central processing unit)
44
a single chip containing a complete CPU
microprocessor
45
the system of a computer that allows the CPU to store programs and information
memory
46
memory used by a computer to store information temporarily
RAM
47
memory used to store basic information that a computer needs to start and for flash memory
ROM
48
computer hardware used for permanent storage of information
mass storage device
49
a device that allows the CPU to communicate with the outside world
input/output device (I/O device)
50
a circuit board that connects all the computer’s components
motherboard
51
stored information and instructions that direct a computer to perform certain tasks
software
52
a single piece of software that directs a computer to perform a certain task
program
53
the worldwide computer network
internet
54
a large, powerful computer designed for rapidly performing complex calculations
supercomputer
55
a versatile, computer-directed machine that can be programmed to perform different tasks
robot
56
type of memory that flash memory would use
ROM
57
method of real-time communication
chat
58
system of using the internet to access remote computer resources, usually to store information
cloud computing
59
small, relatively inexpensive computer designed for one user at a time
PC (personal computer)
60
single piece of software that directs the computer to do a certain task
program
61
SI unit of electric charge
Coulomb
62
some examples of mass storage devices are ____, ____, and _____
hard drives, optical discs, and flash memory
63
connects multiple computers electronically, allowing information to be shared among them
computer networks
64
most software is written in ____
programming language
65
includes all the different programs that direct the computer to perform specific tasks for the user
application software
66
Most system software is part of the _____
operating system (OS)
67
the collection of programs that contain instructions for displaying words and images on the screen for the user to see, saving information on the disk drive, and detecting what the user types on the keyboard
operating system (OS)
68
computers that can be programmed to perform a variety of processing tasks
general-purpose computers
69
“serves” other computers by providing them with requested data
server
70
large computers designed to store and retrieve vast amounts of information
mainframes
71
the study of the nature, behavior, and uses of static electricity and related phenomena
electrostatics
72
a proton has a ____ charge
positive
73
an object with an equal number of positive and negative charges is ____
neutral
74
the simplest form of electricity
static electricity
75
electricity where the charges are stationary
static electricity
76
states that opposite charges attract each other but like charges repel each other
law of electric charges
77
the SI unit of electric charge
Coulomb
78
electric fields can be mapped by _____, which are arrows that indicate how a positive test charge in the field would move
lines of force
79
the method of charge transfer that is permanent is _____
conduction
80
the flow of charge from one place to another
current
81
the SI unit of voltage
volt
82
Electricity that flows first in one direction and then the other, reversing at regular intervals, is called _____
AC (alternating current)
83
the SI unit of current
amp
84
materials through which electricity flows easily
conductors
85
SI unit of resistance
ohm
86
four factors affecting resistance
type of material, diameter of conductor, length of conductor, temperature
87
material allows current to flow with no resistance
superconductor
88
what is Ohm's law
V = IR
voltage = current x resistance
89
three parts of an electric circuit
source of current, conductors, load
90
device that opens and closes a circuit
switch
91
narrow strip of metal housed in a protective insulated case
fuse
92
occurs when electricity takes a shortcut avoiding the load
short circuit
93
an automatic switch that opens the circuit when current flowing through it exceeds a predetermined amount
circuit breaker
94
a circuit in which the loads are arranged so that the electric current flows through each load one after another
series
95
a circuit in which the loads are arranged in separate branches of the circuit and the current is divided among them
parallel circuit
96
regions of concentrated magnetism
poles
97
states that unlike poles attract each other, but like poles repel each other
law of magnetic poles
98
lines that indicate the direction and strength of the magnetic field
lines of flux
99
most important cause of magnetism in magnetic materials
electron spin
100
the extent to which a material can absorb or channel lines of magnetic flux
permeability
101
Lines connecting all points of 0 declination
agonic line
102
Lines connecting all points of 0 inclination
magnetic equator
103
ways to make a stronger electromagnet
add core, increase current, increase coils
104
electric charge always moves ____
to the outside of the object
105
surge of electricity from a cloud to the ground
lightning
106
modern device for storing static electric charge
capacitor
107
first electric light suitable for household use
incandescent lamp
108
three electric discharge lamps
fluorescent, CFL, neon lamp
109
device for converting electricity to back and forth motion
solenoid
110
electrical switch operated by an electromagnet
relay
111
device for converting pulses of electricity into sound waves
loudspeaker
112
Device that can increase or decrease voltage of electric current using electromagnetic induction
transformer
113
three ways to increase current based on electromagnetic induction
add coils, stronger magnet, more motion
114
the negative terminal of a battery
anode
115
the positive terminal of a battery
cathode
116
a group of aligned atoms having a single magnetic field
domain
117
substances with no unpaired electrons
diamagnetic
118
substances that are always slightly repelled by either pole of a magnet
diamagnetic
119
material weakly attracted to a magnet
paramagnetic
120
material with one unpaired electron
paramagnetic
121
materials that are strongly attracted to magnets
ferromagnetic
122
substances with several unpaired electrons
ferromagnetic
123
a device that produces a strong magnetic field when electricity passes through it
electromagnet
124
temperature at which a ferromagnetic material’s domains disappear
Curie point
125
a navigational device consisting of a magnet free to swing horizontally so that it always points north
magnetic compass
126
book published by William Gilbert about his findings on magnetism
De Magnete
127
the deviation of a compass from true north
angle of declination
128
a device that produces static electricity
electrostatic generator
129
a device for communicating over long distances by means of electromagnets
telegraph
130
the most important device for converting electricity into motion
electric motor
131
batteries arranged in ___ increase current
parallel
132
batteries arranged in ____ increase voltage
series
133
a generator in which a conducting fluid passes through a magnetic field at high speed
MHD generator
134
the amount a certain object hinders electron flow
resistance
135
energy divided by time
power
136
work per unit charge done to move electric charges between different parts of an electric field
voltage
