Deck 30: Bipolar Junction Transistors

Question 1

The voltage rating, V_EBO is the maximum allowable ______________-base voltage with the collector open.

Answer 1

emitter

Question 2

For a good p-n junction made of silicon, the ratio R_R/R_F should be equal to or greater than ______________ to 1.

Answer 2

1000

Question 3

Low resistance across the junction in both directions implies that the emitter-base or collector-base junctions are ______________.

Answer 3

shorted

Question 4

The dc load line is a ______________ that allows us to determine all possible combinations of I_C and V_CE for a given amplifier.

Question 5

If a transistor is biased so that it is not operating in saturation or cutoff, it is said to be operating in the ______________ region.

Question 6

The most popular way to bias a transistor is with ______________-divider bias.

Question 7

In computer circuits, the transistor can be used as an electronic ______________.

Question 8

The ______________ region is the largest of all transistor regions.

Question 9

For an NPN transistor schematic symbol, the arrow on the emitter lead points ______________.

Question 10

The symbol h_FE is also used to indicate the dc ______________ of a transistor.

Question 11

When checking a transistor with an ohmmeter

A) base-emitter should be high resistance in both directions
B) base-emitter should be high resistance one way and low the other
C) base-collector should be low resistance in both directions
D) collector-emitter should be low resistance in both directions

Question 12

A control voltage or current is the

A) power factor
B) bias
C) ground
D) load

Question 13

The simplest method to bias a transistor is called

A) base bias
B) voltage-divider bias
C) emitter bias
D) feedback bias

Question 14

If a transistor is biased so that it is not operating in saturation or cutoff, it is said to be operating in the

A) passive region
B) active region
C) nonlinear region
D) bandpass region

Question 15

Without an ac signal applied to a transistor, specific values of I_C and V_CE exist on the dc load line at

A) the Q point
B) cutoff only
C) saturation only
D) the active region only

Question 16

When a transistor is saturated, V_CE is approximately equal to

A) V_CC
B) zero
C) ½ V_CC
D) 6 V

Question 17

For silicon, the barrier potential for both the emitter-base and collector-base junctions equals approximately

A) 0.4 V
B) 0.7 V
C) 1.414 V
D) 3.414 V

Question 18

On the schematic symbol of a bipolar junction transistor, the arrow pointing in indicates

A) the base of an NPN transistor
B) the emitter of a PNP transistor
C) the collector of an NPN transistor
D) the emitter of an NPN transistor

Question 19

Which region of the bipolar junction transistor is heavily doped?

A) Base
B) Collector
C) Emitter
D) Committer

Question 20

For a transistor to operate properly as an amplifier, the emitter-base is

A) forward-biased and the collector-base is reverse-biased
B) reverse-biased and the collector-base is forward-biased
C) forward-biased and the collector-base is forward-biased
D) reverse-biased and the collector-base is reverse-biased

Question 21

A characteristic that describes how closely the emitter and collector currents are in a common base circuit is called the

A) dc beta
B) dc alpha
C) ac beta
D) ac alpha

Question 22

The dc alpha characteristic exhibited in the common base circuit is approximated at

A) 1
B) 1.414
C) 3.414
D) 10

Question 23

The dc current gain of a transistor in the common-emitter connection is called

A) dc beta
B) dc alpha
C) ac beta
D) ac alpha

Question 24

The region of transistor operation where the collector current is zero is called the

A) active region
B) cutoff region
C) breakdown region
D) saturation region

Question 25

The region of transistor operation where the collector of a transistor acts like a current source is called the

A) active region
B) cutoff region
C) breakdown region
D) saturation region

Question 26

The amount that the power rating of a transistor must be reduced for each degree Celsius above 25°C is called the

A) coefficient of coupling
B) power factor
C) derating factor
D) reduction factor

Question 27

A graph that allows a technician to determine all possible combinations of I_C and V_CE for a given amplifier is called the

A) volt-amp characteristic curve
B) Bode plot
C) ac load line
D) dc load line

Question 28

Transistors are used when it is necessary to amplify voltage, current, or power.

Question 29

A transistor's output signal can be hundreds or even thousands of times larger than the input signal.

Question 30

The transistor cannot be used as an electronic switch in computer circuits.

Question 31

A transistor has two doped regions.

Question 32

The emitter's job is to inject current carriers into the base.

Question 33

In the pnp transistor, the majority current carriers are free electrons in the emitter and collector.

Question 34

For the NPN transistor schematic symbol the arrow on the emitter lead points outward.

Question 35

The base of a bipolar junction transistor is very thin and lightly doped.

Question 36

In a common-base connection, the emitter lead is common to both the input and output side of the circuit.

Question 37

The dc current gain of a transistor in the common-emitter connection is called dc beta.

Question 38

The symbol h_FE is also used to indicate the dc beta of a transistor.

Question 39

When displayed on a curve tracer, collector curves actually have a slight upward slope as V_CE increases.

Question 40

When a transistor is saturated, further increases in base current produce further increases in collector current.

Question 41

The breakdown region is that region of transistor operation where a large undesired collector current flows as a result of the collector-base diode breaking down from excessive reverse-bias voltage.

Question 42

An analog ohmmeter can be used to check a transistor because the emitter-base and collector-base junctions are p-n junctions.