NAVEDTRA 14179A, NEETS Mod. 7, Ch. 1 Flashcards
What are two of the most widely known semiconductors that are in use today?
Junction diode and the Transistor
Which type of device operates by virtue of the movement of electrons within a solid piece of semiconductor material?
Solid-state
What is a minute piece of semiconductor material that can produce complete electronic circuit functions?
Integrated circuit
Which year did Michael Faraday discover that silver sulfide, a semiconductor, has a negative temperature coefficient?
1883
Which year did Munk A. Rosenshold find that certain materials have rectifying properties?
1885
Who invented the photophone?
Alexander Graham Bell
Which material used in communications was found to be the most stable?
Silicon
Which type of material was found to be the most sensitive for use in early radio receivers?
Galena
What could be designed to work within the ultra-high frequencies used in radar, whereas the electron tube could not?
Point-contact semiconductor diode
Whose initial work led to the development of zener diode which is frequently used today to regulate power supply voltages at precise levels?
Dr. Carl Zener
The maximum allowable voltage for a transistor is limited to about 200 volts (but usually how many volts or less)?
50
The maximum power output for transistor generally ranges from 30 milliwatts to slightly over how many watts?
100
Which two parts is the universe, as we know it today, divided into?
Matter and energy
What is anything that occupies space and has weight known as?
Matter
What are the three states that matter may be found in?
Solids, liquids, and gases
What is a chemical combination of two or more elements called?
Compound
What is the smallest part of a compound called which has all the characteristics of the compound?
Molecule
What carries a positive charge of electricity equal and opposite to the charge of the electron?
Proton
Approximately how many times is the mass of the proton to that of an electron?
1,827
What has a mass approximately equal to that of a proton but has no electrical charge?
Neutron
What is a list of all the known elements with the number of electrons in each atom contained?
Periodic table of elements
What is an atom’s ability to combine with other atoms called?
Valence
What is the outer shell of an atom called?
Valence shell
In simple terms, energy is required in definite units to move electrons from one shell to the next higher shell. What are these units called?
Quanta
In which process does an atom lose or gain electrons?
Ionization
Which band are electrons never found in, but may travel back and forth through it, provided they do not come to rest in the band?
Forbidden
The conduction band along with which other band are the two energy bands that an electron can exist in?
Valence
The chemical activity of an atom is determined by the number of what in its valence shell?
Electrons
What is a solid whose atoms or molecules are arranged in a three-dimensional geometrical pattern commonly referred to as a lattice called?
Crystal
Arsenic, antimony, bismuth, and phosphorous are all what type of impurities?
Pentavalent
Aluminum, indium, gallium, and boron are all what type of impurities?
Trivalent
Which type of device is obtained when a section of N-type semiconductor material is joined with a similar section of P-type semiconductor material?
PN Junction
What is the overall charge of N material?
Zero
What is the electrostatic field called that is created by the positive and negative ions in the depletion region?
Barrier
What is an external voltage applied to a PN junction called?
Bias
What offers very little resistance to current flow in the forward-bias direction but maximum resistance to current flow when reverse biased?
PN junction diode
What is one of the most important uses of a diode?
Rectification
What is the simplest type of rectifier circuit?
Half-wave rectifier
What is any device that draws current defined as?
Load
There are many known metal-semiconductor combinations that can be used for contact rectification. Which devices are by far the most popular?
Copper oxide and selenium
Copper-oxide rectifiers are generally used in small-current applications such as AC meter movements or for delivering direct current to circuits requiring not more than how many amperes?
10
What is the maximum reverse DC voltage that will not cause breakdown called?
DC Blocking voltage
What temperature is the maximum average forward current usually given at?
77 degrees F
What is the maximum current called that is permitted to flow in the forward direction in the form of nonrecurring pulses?
Maximum surge current
What indicates the maximum reverse-bias voltage that may be applied to a diode without causing junction breakdown?
PRV
PRV
What is the most convenient and quickest way of testing a diode?
Ohmmeter
Which substance cannot be reduced to a simpler form by chemical means?
Element
What is the smallest particle into which an element can be broken down and still retain all its original properties?
Atom
What is the amount of energy required by an electron to stay in orbit?
Electron energy level
What is the process by which small amounts of selected additives, called impurities, are added to semiconductors to increase their current flow?
Doping
