NAVEDTRA 14179A, NEETS Mod. 7, Ch. 1

Question 1

What are two of the most widely known semiconductors that are in use today?

Answer 1

Junction diode and the Transistor

Question 2

Which type of device operates by virtue of the movement of electrons within a solid piece of semiconductor material?

Answer 2

Solid-state

Question 3

What is a minute piece of semiconductor material that can produce complete electronic circuit functions?

Answer 3

Integrated circuit

Question 4

Which year did Michael Faraday discover that silver sulfide, a semiconductor, has a negative temperature coefficient?

Answer 4

1883

Question 5

Which year did Munk A. Rosenshold find that certain materials have rectifying properties?

Answer 5

1885

Question 6

Who invented the photophone?

Answer 6

Alexander Graham Bell

Question 7

Which material used in communications was found to be the most stable?

Answer 7

Silicon

Question 8

Which type of material was found to be the most sensitive for use in early radio receivers?

Answer 8

Galena

Question 9

What could be designed to work within the ultra-high frequencies used in radar, whereas the electron tube could not? 



Answer 9

Point-contact semiconductor diode

Question 10

Whose initial work led to the development of zener diode which is frequently used today to regulate power supply voltages at precise levels?

Answer 10

Dr. Carl Zener

Question 11

The maximum allowable voltage for a transistor is limited to about 200 volts (but usually how many volts or less)?

Answer 11

50

Question 12

The maximum power output for transistor generally ranges from 30 milliwatts to slightly over how many watts?

Answer 12

100

Question 13

Which two parts is the universe, as we know it today, divided into?

Answer 13

Matter and energy

Question 14

What is anything that occupies space and has weight known as?

Answer 14

Matter

Question 15

What are the three states that matter may be found in?

Answer 15

Solids, liquids, and gases

Question 16

What is a chemical combination of two or more elements called?

Answer 16

Compound

Question 17

What is the smallest part of a compound called which has all the characteristics of the compound?

Answer 17

Molecule

Question 18

What carries a positive charge of electricity equal and opposite to the charge of the electron?

Answer 18

Proton

Question 19

Approximately how many times is the mass of the proton to that of an electron?

Answer 19

1,827

Question 20

What has a mass approximately equal to that of a proton but has no electrical charge?

Answer 20

Neutron

Question 21

What is a list of all the known elements with the number of electrons in each atom contained?

Answer 21

Periodic table of elements

Question 22

What is an atom’s ability to combine with other atoms called?

Answer 22

Valence

Question 23

What is the outer shell of an atom called?

Answer 23

Valence shell

Question 24

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? 



Answer 24

Quanta

Question 25

In which process does an atom lose or gain electrons?

Answer 25

Ionization

Question 26

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?

Answer 26

Forbidden

Question 27

The conduction band along with which other band are the two energy bands that an electron can exist in?

Answer 27

Valence

Question 28

The chemical activity of an atom is determined by the number of what in its valence shell?

Answer 28

Electrons

Question 29

What is a solid whose atoms or molecules are arranged in a three-dimensional geometrical pattern commonly referred to as a lattice called?

Answer 29

Crystal

Question 30

Arsenic, antimony, bismuth, and phosphorous are all what type of impurities?

Answer 30

Pentavalent

Question 31

Aluminum, indium, gallium, and boron are all what type of impurities?

Answer 31

Trivalent

Question 32

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?

Answer 32

PN Junction

Question 33

What is the overall charge of N material?

Answer 33

Zero

Question 34

What is the electrostatic field called that is created by the positive and negative ions in the depletion region?


Answer 34

Barrier

Question 35

What is an external voltage applied to a PN junction called?

Answer 35

Bias

Question 36

What offers very little resistance to current flow in the forward-bias direction but maximum resistance to current flow when reverse biased? 



Answer 36

PN junction diode

Question 37

What is one of the most important uses of a diode?

Answer 37

Rectification

Question 38

What is the simplest type of rectifier circuit?

Answer 38

Half-wave rectifier

Question 39

What is any device that draws current defined as?

Answer 39

Load

Question 40

There are many known metal-semiconductor combinations that can be used for contact rectification. Which devices are by far the most popular? 


Answer 40

Copper oxide and selenium

Question 41

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?

Answer 41

10

Question 42

What is the maximum reverse DC voltage that will not cause breakdown called?

Answer 42

DC Blocking voltage

Question 43

What temperature is the maximum average forward current usually given at?

Answer 43

77 degrees F

Question 44

What is the maximum current called that is permitted to flow in the forward direction in the form of nonrecurring pulses?

Answer 44

Maximum surge current

Question 45

What indicates the maximum reverse-bias voltage that may be applied to a diode without causing junction breakdown? PRV

Answer 45

PRV

Question 46

What is the most convenient and quickest way of testing a diode?

Answer 46

Ohmmeter

Question 47

Which substance cannot be reduced to a simpler form by chemical means?

Answer 47

Element

Question 48

What is the smallest particle into which an element can be broken down and still retain all its original properties? 


Answer 48

Atom

Question 49

What is the amount of energy required by an electron to stay in orbit?

Answer 49

Electron energy level

Question 50

What is the process by which small amounts of selected additives, called impurities, are added to semiconductors to increase their current flow?

Answer 50

Doping