W/S

Question 1

A semiconductor atom, such as silicon, contains how many valence electrons?

Answer 1

four

Question 2

What is the name given to semiconductor materials that are doped with trivalent impurity atoms?

Answer 2

P-type

Question 3

What is the name given to semiconductor materials that are doped with pentavalent impurity atoms?

Answer 3

N-type

Question 4

Semiconductor materials exhibit a “negative temperature coefficient of resistance” . What does this mean?

Answer 4

as temp increases, resistance decreases

Question 5

What is the typical voltage drop expected across a silicon diode that is conducting in the forward direction?

Answer 5

0.7v

Question 6

What does the term “PIV” mean?

Answer 6

“Peak inverse voltage” The max reverse biased voltage the diode can block

Question 7

In order to conduct, the polarity of the cathode must be ____________ with respect to the anode

Answer 7

negative

Question 8

When using an ohmmeter for testing a diode, what indication would you expect if the diode is?

a) shorted?
b) open?
c) good?

Answer 8

a) low in both directions
b) high in both directions
c) low in forward bias and high in reverse bias

Question 9

When pure silicon is doors with trivalent material, a ______-type material is produced with an excess of ________?

Answer 9

P- type

holes

Question 10

When pure silicon is doped with a pentavalent material, a ______-type material is produced with an excess of _________?

Answer 10

N- type , electrons

Question 11

What is meant when silicon has a negative temperature coefficient?

Answer 11

as temp rises, resistance goes down

Question 12

forward voltage drop for a silicon diode?

Answer 12

0.7v

Question 13

Forward voltage drop for a germanium diode?

Answer 13

0.3v

Question 14

When reverse biased, does a silicon diode act as a conductor or as an open?

Answer 14

open

Question 15

When using a digital multimeter diode checker, what value does the meter read if the diode is good? (approx)

Answer 15

600mV

Question 16

When installing a freewheeling diode, how should the diode be installed?

Answer 16

reverse bias to load

Question 17

What is the process called that mixes pure silicon and an impurity?

Answer 17

doping

Question 18

What determines whether a material is a conductor or a semiconductor?

Answer 18

number of valence electrons

Question 19

Why is silicon used more as a semiconductor than germanium?

Answer 19

withstands higher temp

Question 20

What is the name of the device that sheds heat around a semiconductor?

Answer 20

heat sink

Question 21

What is meant by the term “forward bias”?

Answer 21

anode is positive with respect to cathode

Question 22

what is meant by the term “reverse bias”?

Answer 22

anode is negative with respect to the cathode

Question 23

what are two leads of a diode called?

Answer 23

anode and cathode

Question 24

what is a “free-wheeling diode”?

Answer 24

In parallel with the winding and used as circuit protection

Question 25

How do we reverse bias a diode?

Answer 25

reverse polarities

Question 26

Increasing the amount of light falling on a photodiode will___________ the current going through it?

Answer 26

increase

Question 27

In order for a zener diode to act as a voltage regulator it must be in __________ with the load and ________ biased?

Answer 27

series

reverse

Question 28

To forward bias a diode we want the _______ to be more positive than the _________?

Answer 28

anode

cathode

Question 29

What is the purpose of a field discharge diode?

Answer 29

prevent arcing

Question 30

barrier potential for a germanium diode?

Answer 30

.3v

Question 31

typical range of forward current rating for rectifier diodes?

Answer 31

1-1000

Question 32

using an ohmmeter to check a diode, with the leads hooked up in either polarity, an infinite reading was observed. What is wrong with the diode?

Answer 32

It’s open

Question 33

Gallium is often used as an impurity for doping purposes for the ___________anode/cathode of a diode?

Answer 33

anode

Question 34

the majority current carries in a semiconductor substrate doped with arsenic are ___________ electrons/holes?

Answer 34

electrons

Question 35

In order for a rectifier diode to conduct, the PN junction must be ______ biased?

Answer 35

forward