Science Exam Flashcards
a branch of the study of electricity that deals with the behavior and motion of electrons in a vacuum or in semiconductors
electronics
negative electrode of a vacuum tube
cathode
positive electrode of a vacuum tube
anode
glass tube containing electrodes sealed in a vacuum
vacuum tube
Early experimenters with vacuum tubes knew something was crossing the gap between electrodes in a vacuum, so they named them ______
cathode rays
designed so that the cathode rays would miss the anode and strike the end of the glass tube instead
cathode-ray tube (Crookes tube)
special type of vacuum tube to study cathode rays
cathode-ray tube (Crookes tube)
cathode-ray tube designed to generate x-rays
x-ray tube
tube designed to generate rays that were originally unknown
x-ray tube
The production of an electric current in a vacuum using a heated cathode
thermionic emission (Edison effect)
a vacuum tube in which current only flows one direction; has 2 electrodes
diode
a simple vacuum tube consisting of two electrodes
diode
a vacuum tube with three electrodes
triode
_____ acts as a very fast electronic switch
triode
a material that is neither a good conductor nor a good insulator
semiconductor
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
doping
material with extra electrons that are free to move
n-type semiconductor
material with extra holes lacking negative charge
p-type semiconductor
semiconductor device that, like a vacuum-tube diode, allows current to pass in only one direction
semiconductor diode
True or false: a p-n junction allows current to flow in only one direction
true
a semiconductor device that can perform the same functions as a vacuum-tube triode, such as acting as a “switch” and amplifying weak signals
transistor
A semiconductor device that produces electric current through the separation of charges through light
photovoltaic cell
devices that consist of solid crystals of semiconductor
solid-state devices
the most common type of transistor used today
FET (field-effect transistor) - found in computer chips
semiconductor diode that emits visible light when an electric current is applied
LED
device consisting of a single piece of semiconductor containing an entire electronic circuit
integrated circuit (chip)
three benefits of integrated circuits
- smaller
- cheaper
- more reliable
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
device that processes information using electronic circuits
computer
pieces of information
data
America’s first mass-produced computer
UNIVAC 1
first general-purpose electronic computer
ENIAC
The modern computer era is said to have begun with the completion of ______
ENIAC
random variations that affect any signal
noise
data that can have any possible value within a specified range
analog data
data that can have only certain values within a range
digital data
practically all modern electronic computers are _____ computers
digital
number system based on powers of 2
binary number system
number system based on powers of 16
hexadecimal number system
computer coding system upon which most other common coding systems are based
ASCII
a device that produces a single binary output based on one or more binary inputs
logic gate
the physical components of a computer
hardware
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)
a single chip containing a complete CPU
microprocessor
the system of a computer that allows the CPU to store programs and information
memory
memory used by a computer to store information temporarily
RAM
memory used to store basic information that a computer needs to start and for flash memory
ROM
computer hardware used for permanent storage of information
mass storage device
a device that allows the CPU to communicate with the outside world
input/output device (I/O device)
a circuit board that connects all the computer’s components
motherboard
stored information and instructions that direct a computer to perform certain tasks
software
a single piece of software that directs a computer to perform a certain task
program
the worldwide computer network
internet
a large, powerful computer designed for rapidly performing complex calculations
supercomputer