Semiconductor & PN Junction

Question 1

The best electrical conductors are…….

Answer 1

silver, copper and aluminum

Question 1

The atom of a material used as a conductor generally contain _______.

Answer 1

1 or 2 valence electron

Question 2

Solid-state devices, such as diodes and transistors, are often called

Answer 2

Semiconductor

Question 3

The word _________ refers to the type of material used to make solid-state devices.

Answer 3

Semiconductor

Question 4

An atom that has only one valence electron makes the best conductor because the electron is held loosely in orbit and is easily given up for current flow. True or False

Answer 4

True

Question 5

How many valence electron does insulator have?

Answer 5

7 to 8 valence electron

Question 6

How many valence electron shall be consider semiconductor?

Answer 6

4 valence electron

Question 7

What are the most common semiconductors materials used in the electronics field?

Answer 7

1. Germanium
2. Silicon

Question 8

When molecules arrange themselves into a crystal structure with a definite pattern. This pattern is called _______.

Answer 8

Lattice structure

Question 9

When pure semiconductor material is mixed with an impurity that has only three valence electrons, such as indium or gallium, _________

Answer 9

the lattice structure changes, leaving a hole in the material

Question 10

A semi-conductor material with a net positive charge are known as a ___________.

Answer 10

P-type material

Question 11

A semi-conductor material with a net negative charge are known as a ___________.

Answer 11

N-type material

Question 12

How is a P-type material made?

Answer 12

When pure semiconductor material is mixed with an impurity that has only three valence electrons, the lattice structure changes, leaving a hole in the material. The hole, which has taken place of an electron, has a positive charge

Question 13

How is a N-type material made?

Answer 13

When a semiconductor material is mixed with an impurity that has five valence electron, the lattice structure has an excess of electrons meaning that the material has a net negative charge. t

Question 14

Which type of semiconductor material can withstand the greatest amount of heat?

Answer 14

Silicon is used more often because of its ability to withstand heat.

Question 15

how the PN junction (diode) produced?

Answer 15

A PN junction is produced by joining p-type and n-type semiconductor materials.

Question 16

Solid-state devices are made by______________ materials

Answer 16

combination P-type and N-type

Question 17

How does diode operates in circuit?

Question 18

What is doping

Question 19

An outer orbits of the atoms of material are filled or almost filled with valence are known as _______.

Answer 19

Insulator

Question 20

What is Semiconductor?

Answer 20

elements have exactly four valence electrons and are therefore considered neither good conductors nor good insulators.

Question 21

Why silicon use more often?

Answer 21

Its ability to withstand heat.

Question 22

The two common semi conductor are:

Answer 22

1. Germanium
2. Silicon

Question 23

Germanium diodes have a lower forward voltage drop about _______.

Answer 23

0.3 volt

Question 24

What is covalent bonding?

Answer 24

Atoms share electrons to fill their valence shells. Each shared pair of electrons constitutes a covalent bond

Question 25

The atoms of purified semiconductor materials arrange themselves into a unique pattern known as a

Answer 25

Crystal-lattice structure

Question 26

The atoms of the impurity are injected into the crystal through a process know as

Answer 26

Doping

Question 27

An N-type semiconductor is formed when an impurity having five valence electrons is introduced into the pure semiconductor crystal. This impurity is said to be______

Answer 27

Pentavalent

Question 28

when a semiconductor material is mixed with an impurity that has five valence electrons, such as arsenic or antimony, the lattice structure has an ______

Answer 28

Excess of electron. meaning that the material has a net negative charge which is N-Type

Question 29

All solid-state devices are made from combination of _

Answer 29

P and N-type material

Question 30

How do you determine type of devices?

Answer 30

The number of layer of material and the thickness of each layer

Question 31

Diode is often called a __________ because it is made by joining a piece of P-type material and a piece of N-type material

Answer 31

PN junction

Question 32

what device is made by join three layers of semiconductor materials

Answer 32

Transistor

Question 33

What is a rectifier?

Answer 33

A rectifier is a device that changes, or converts, AC voltage into DC voltage.

Question 34

A positive voltage connected to anode is known as which bias?

Answer 34

Forward bias

Question 35

What are the two types of rectifier are:

Answer 35

Half-wave and Full-wave

Question 36

How many diodes are required to construct the bridge rectifier?

Answer 36

4 diodes

Question 37

An P-type semiconductor is formed when an impurity having three valence electrons is introduced into the pure semiconductor crystal. This impurity is said to be______

Answer 37

Trivalent

Question 38

Semiconductor are not easily destroyed by heat? True or False?

Answer 38

False, semiconductor is easily destroyed by heat

Question 39

It is VERY IMPORTANT to operate semiconductors within their

Answer 39

Voltage, current and temperature limits

Question 40

If the ohm meter indicate very low resistance, the diode is_________.

Answer 40

forward bias

Question 41

If the ohm meter indicate very high resistance, the diode is_________.

Answer 41

reversed bias

Question 42

when using a multi-meter on the diode checker, what value does the meter read if the diode is good?

Answer 42

600mV

Question 43

The half-wave rectifier can be constructed using only_________.

Answer 43

one diode

Question 44

As the temperature increases, the resistance _________. So the conductivity ____________.

Answer 44

Decrease, increase

Question 45

What is the purpose of have heat sink?

Answer 45

To improve the dissipation of heat because of internal R losses in semiconductor devices such as diodes and transistors

Question 46

The voltage drops for germanium is _________.

Answer 46

0.3 V

Question 47

The P-type material gains some electrons (negative charge), and the N-type material loses some electrons (positive charge). Therefore, a small __________________ is formed at the junction.

Answer 47

Barrier Potential

Question 48

What element is mixed with impurity that has only three valence electrons.

Answer 48

Indium or gallium

Question 49

What element is mixed with impurity that has only five valence electrons.

Answer 49

arsenic or antimony

Question 50

A diode is NOT made by joining piece of P-type material and a piece of N-type material together. True or false?

Answer 50

False.

Question 51

What is a term "avalanche"

Question 52

3 significant rating for rectifier diodes are

Answer 52

1. forward current voltage 2.