semiconductor diodes

Question 1

Which of the following devices can check the condition of a semiconductor diode?
A) Digital display meter (DDM)
B) Multimeter
C) Curve tracer
D) All of the above

Answer 1

D

Question 2

How many orbiting electrons does the germanium atom have?

Answer 2

32

Question 3

What is the range of the operating voltage level for LEDs?

Answer 3

1.7–3.3 V

Question 4

The _________ diode model is employed most frequently in the analysis of electronic systems.

Answer 4

simplified

Question 5

The forward characteristics curve of a diode grows in _______ form.

Answer 5

exponential

Question 6

Diodes are connected _______ to increase the current-carrying capacity.

Answer 6

in parallel

Question 7

A(n) _______ is the simplest of semiconductor devices.

Answer 7

diode

Question 8

In the atomic lattice the _______ and _______ form the nucleus.

Answer 8

neutrons, protons

Question 9

It is not uncommon for a germanium diode with an Is in the order of 1–2 A at 25°C to have leakage current of 0.1 mA at a temperature of 100°C. True or False.

Answer 9

True

Question 10

How many valence electrons does a silicon atom have?

Answer 10

4

Question 11

In which of the following is the light intensity measured?

Answer 11

Candela

Question 12

Varying the _______ can control the location of the Zener region.

Answer 12

doping levels

Question 13

The ac resistance of a diode is the _______ of the characteristic curve at the Q-point of operation.

Answer 13

reciprocal of the slope

Question 14

The intensity of LED is greatest at _______ degrees and the least at _______ degrees.

Answer 14

0, 90

Question 15

At what kind of operating frequency diffusion or transition is a capacitor represented in parallel with the ideal diode?

A) Low frequency
B) Moderate frequency
C) Mid frequency
D) Very high frequency

Answer 15

D) Very high frequency

Question 16

The diode _______.

A) is the simplest of semiconductor devices
B) has characteristics that closely match those of a simple switch
C) is a two-terminal device
D) All of the above

Answer 16

D) All of the above

Question 17

In n-type material the _______ is called the majority carrier.

Answer 17

electron

Question 18

The diffused impurities with _______ valence electrons are called acceptor atoms.

Answer 18

3

Question 19

What is the state of an ideal diode in the region of nonconduction?

Answer 19

An open circuit

Question 20

The condition of a semiconductor diode can be determined quickly using a _________.

A) DDM
B) VOM
C) curve tracer
D) Any of the above

Answer 20

D) Any of the above

Question 21

The test current in a Zener diode IZT is the current defined by the _______ power level.

Answer 21

0.25

Question 22

Calculate the temperature coefficient in %/°C of a 10-V nominal Zener diode at 25°C if the nominal voltage is 10.2 V at 100°C.

Answer 22

0.0267

Question 23

Which of the following ratings is true?

A) Si diodes have higher PIV and narrower temperature ranges than Ge diodes.
B) Si diodes have higher PIV and wider temperature ranges than Ge diodes.
C) Si diodes have lower PIV and narrower temperature ranges than Ge diodes.
D) Si diodes have lower PIV and wider temperature ranges than Ge diodes.

Answer 23

B) Si diodes have higher PIV and wider temperature ranges than Ge diodes.

Question 24

What does a high resistance reading in both forward- and reverse-bias directions indicate?

A) A good diode
B) An open diode
C) A shorted diode
D) A defective ohmmeter

Answer 24

B) An open diode

Question 25

One eV is equal to _______ J.

Answer 25

1.6 × 10^–19

Question 26

Which of the following elements is most frequently used for doping pure Ge or Si? A) Boron B) Gallium C) Indium D) All of the above

Answer 26

D) All of the above

Question 27

What is the maximum power rating for LEDs?

Answer 27

150 mW

Question 28

Calculate the power dissipation of a diode having ID = 40 mA.

Answer 28

28 mW

Question 29

Which capacitance dominates in the reverse-bias region? A) depletion B) conversion C) Diffusion D) None of the above

Answer 29

A) depletion

Question 30

Any electron that has left its parent atom has _______ energy state relative to any electron in the atomic structure. A) the same B) a lower C) a higher D) an undefined

Answer 30

C) a higher

Question 31

The diffused impurities with ________ valence electrons are called donor atoms.

Answer 31

5

Question 32

The potential at which the characteristics curve vertical rise occurs is commonly referred to as the _______. A) offset B) threshold C) firing potential D) All of the above

Answer 32

D) All of the above

Question 33

Which capacitance dominates in the forward-bias region? A) Diffusion B) Transition C) Depletion D) None of the above

Answer 33

A) Diffusion

Question 34

Determining rd to a high degree of accuracy from a characteristic curve is very accurate. A) True B) False

Answer 34

B) False

Question 35

Calculate static resistance RD of a diode having ID = 30 mA and VD = 0.75 V.

Answer 35

25

Question 36

Generally the value of ac resistance is _______ the value of dc resistance at the same operating point. A) smaller than B) larger than C) the same as D) unrelated to

Answer 36

A) smaller than

Question 37

The reverse-saturation current level is typically measured in _______. A) pA B) µA C) mA D) A

Answer 37

B) µA

Question 38

The heavier the current in a Zener diode in reverse bias, _______ dynamic resistance value. A) the more the B) the less the C) there is substantially more D) there is no change in the

Answer 38

B) the less the

Question 39

The reverse-bias current _______ with the increase of temperature. A) decreases B) increases C) remains the same D) None of the above

Answer 39

B) increases

Question 40

The temperature coefficient can be _______ for different Zener levels. A) positive B) negative C) zero D) All of the above

Answer 40

D) All of the above

Question 41

The term ________ is often used when comparing the resistance level of materials.

Answer 41

resistivity

Question 42

How many terminals does a diode have?

Answer 42

2

Question 43

In general, LEDs operate at voltage levels from _____ V to _____ V.

Answer 43

1.7, 3.3

Question 44

What is the value of the transition capacitance for a silicon diode when VD = 0?

Answer 44

3 pF

Question 45

The _______ the current through a diode, the _______ the dc resistance level. A) higher, lower B) lower, lower C) lower, higher D) higher, higher

Answer 45

C) lower, higher

Question 46

The reverse saturation current Is will just _______ in magnitude for every 10° C increase in temperature. A) double B) remain the same C) halve D) triple

Answer 46

A) double

Question 47

Determine the nominal voltage for the Zener diode at a temperature of 120°C if the nominal voltage is 5.1 volts at 25°C and the temperature coefficient is 0.05%/°C.

Answer 47

5.34 V

Question 48

The ideal diode is a(n) _______ circuit in the region of nonconduction. A) open B) short

Answer 48

A) open

Question 49

In which of the following color(s) is (are) LEDs presently available? A) Yellow B) White C) Orange D) All of the above

Answer 49

D) All of the above

Question 50

Calculate ID if RD = 30 and VD = 0.84 V.

Answer 50

28 mA