Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ELEX > BJT FLOYD > Flashcards

BJT FLOYD Flashcards

1
Q

The three terminals of a bipolar junction transistor are
called
A. input, output, ground
B. base, emitter, collector
C. p,n,p
D. n,p,n

A

B. base, emitter, collector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  1. In a pnp transistor, the p-region are
    A. base and emitter
    B. base and collector
    C. emitter and collector
A

C. emitter and collector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  1. For operation as an amplifier, the base of a npn
    transistor must be
    A. 0 V
    B. negative with respect to the emitter
    C. positive with respect to the collector
    D. positive with respect to the emitter
A

D. positive with respect to the emitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  1. The emitter current is always
    A. greater than the base current
    B. less than the collector current
    C. greater than the collector current
    D. answer a and c
A

D. answer a and c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. The βDC of a transistor is its
    A. internal resistance
    B. power gain
    C. voltage gain
    D. current gain
A

D. current gain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  1. If IC is 50 times larger than IB, then βDC is
    A. 500
    B. 0.02
    C. 100
    D. 50
A

D. 50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  1. The approximate voltage across the forward-biased base
    emitter junction of a silicon BJT is
    A. 0.3 V
    B. 0.7 V
    C. 0 V
    D. VBB
A

B. 0.7 V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  1. The bias condition for a transistor to be used as linear
    amplifier is called
    A. reverse-reverse
    B. forward-reverse
    C. collector bias
    D. forward-forward
A

B. forward-reverse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  1. If the output of a transistor amplifier is 5 V rms and the
    input is 100 mV rms, the voltage gain is
    A. 50
    B. 500
    C. 5
    D. 100
A

A. 50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  1. When operated in cutoff and saturation, the transistor
    acts like
    A. a switch
    B. a linear amplifier
    C. a variable capacitor D. a variable resistor
A

A. a switch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. In cutoff, VCE is
    A. 0 V
    B. minimum
    C. maximum
    D. equal to VCC
    E. answer a and b
    F. answer c and d
A

F. answer c and d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  1. In saturation, VCE is
    A. 0.7 V
    B. equal to VCC
    C. maximum
    D. minimum
A

D. minimum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  1. To saturate a BJT,
    A. IB > IC(sat)/βDC
    B. IB = IC(sat)
    C. VCC must be at least 10 V
    D. the emitter must be grounded
A

A. IB > IC(sat)/βDC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  1. Once in saturation, a further increase in base current will
    A. not affected the collector current
    B. cause the collector current to decrease
    C. cause the collector current to increase
    D. turn the transistor off
A

A. not affected the collector current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. If the base-emitter junction is open, the collector voltage
    is
    A. floating
    B. VCC
    C. 0 V
    D. 0.2 V
A

B. VCC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  1. The maximum value of collector current in a biased
    transistor is
    A. βDCIB
    B. IC(sat)
    C. greater than IE
    D. IE - IB
A

B. IC(sat)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
  1. Ideally, a dc load line is s straight line drawn on the
    collector characteristics curves between
    A. the Q-point and saturation
    B. VCE(cut off) and IC(sat)
    C. the Q-point and cut-off
    D. IB = 0 and IB = IC / βDC
A

B. VCE(cut off) and IC(sat)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  1. If a sinusoidal voltage is applied to the base of a biased
    npn transistor and the resulting sinusoidal collector
    voltage is clipped near zero volts, the transistor is
    A. being driven into saturation
    B. being driven into cut off
    C. operating nonlinearly
    D. answer a and c
    E. answer b and c
A

E. answer b and c

19
Q
  1. The input resistance at the base of a biased transistor
    depends mainly on
    A. βDC
    B. βDC and RE
    C. RB
    D. RE
A

B. βDC and RE

20
Q
  1. In a voltage-divider biased transistor circuit such as
    Figure 5 –13, RIN(base) can generally be neglected in
    calculation when
    A. RIN(base) > 10 R2
    B. R1 &laquo_space;R2
    C. RIN(base) > R2
    D. R2 > 10 RIN(base)
A

A. RIN(base) > 10 R2

21
Q
  1. In a certain voltage-divider biased npn transistor, VB is
    2.95 V. The dc emitter voltage is approximately
    A. 2.95 V
    B. 2.25 V
    C. 0.7 V
    D. 3.65 V
A

B. 2.25 V

22
Q
  1. Voltage-divider bias
    A. can be essentially independent of βDC
    B. is not widely used
    C. cannot be independent of βDC
    D. requires fewer components than all the other
    methods
A

A. can be essentially independent of βDC

23
Q
  1. The disadvantage of base bias is that
    A. it produces low gain
    B. it is very complex
    C. it produces high leakage current
    D. it is too beta dependent
A

C. it produces high leakage current

24
Q
  1. Emitter bias is
    A. essentially independent of βDC
    B. very dependent of βDC
    C. provides a stable bias point
    D. answer a and c
A

D. answer a and c

25
Q
  1. In an emitter bias circuit, RE = 2.7 k Ω and VEE = 15 V. The
    emitter current
    A. is 180 mA
    B. is 2.7 mA
    C. is 5.3 mA
    D. cannot be determined
A

C. is 5.3 mA

26
Q
  1. Collector-feedback bias is
    A. based on the principle of negative feedback
    B. based on beta multiplication
    C. based on the principle of positive feedback
    D. not very stable
A

A. based on the principle of negative feedback

27
Q
  1. In a voltage-divider biased npn transistor, if the upper
    voltage-divider resistor (the one connected to VCC opens,
    A. the transistor burns out
    B. the transistor goes into saturation
    C. the transistor goes into cutoff
    D. the supply voltage is too high
A

C. the transistor goes into cutoff

28
Q
  1. In a voltage-divider biased npn transistor, if the lower
    voltage-divider resistor (the one connected to VCC) opens.
    A. the collector current will decrease
    B. the transistor may be driven into saturation
    C. the transistor is not affected
    D. the transistor may be driven into cutoff
A

B. the transistor may be driven into saturation

29
Q
  1. In a voltage-divider biased pnp transistor, there is no
    base current, but the base voltage is approximately
    correct. The most likely problem(s) is
    A. a bias resistor is open
    B. the collector resistor is open
    C. the base-emitter junction is open
    D. the emitter resistor is open
    E. answer a and c
    F. answer c and d
A

F. answer c and d

30
Q
  1. A small-signal amplifier
    A. is always a common-emitter amplifier
    B. always has an output signal in the mV range
    C. uses only a small portion of its load line
    D. goes into saturation once on each input cycle
A

C. uses only a small portion of its load line

31
Q
  1. The parameter hfe corresponds to
    A. βAC
    B. βDC
    C. r’c
    D. r’e
A

A. βAC

32
Q
  1. If the dc emitter current in a certain transistor amplifier
    is 3 mA, the approximate value of r’e is
    A. 3 Ω B. 3 kΩ
    C. 0.33 kΩ D. 8.33 Ω
A

D. 8.33 Ω

33
Q
  1. A certain common-emitter amplifier has a voltage gain of
  2. If the emitter bypass capacitor is removed,
    A. the voltage gain will decrease
    B. the voltage gain will increase
    C. the circuit will become unstable.
    D. the Q-point will shift
A

A. the voltage gain will decrease

34
Q
  1. For a common-collector amplifier, RE = 100 Ω, r’e = 10 Ω,
    and βAC = 150. The ac input resistance at the base is
    A. 16.5 Ω B. 15 kΩ
    C. 110 Ω D. 1500 Ω
A

A. 16.5 Ω

35
Q

100.If a 10 mV signal is applied to the base of the emitter-
follower circuit in Question 5, the output signal is

approximately
A. 1.5 mV B. 10 mV
C. 100 mV D. 150 mV

A

B. 10 mV

36
Q

101.For a common-emitter amplifier, RC = 1.0 kΩ, RE = 390 Ω,
and βac = 75. Assuming the RE is completely bypassed at
the operating frequency, the voltage gain is
A. 2.56 B. 66.7
C. 2.47 D. 75

A

B. 66.7

37
Q

102.In the circuit of Question 7, if the frequency is reduced to
the point where XC(bypass) = RE, the voltage gain
A. remains the same
B. is less
C. is greater D.

A

B. is less

38
Q

103.In a certain emitter-follower circuit, the current gain is
50. The power gain is approximately
A. 50 AV
B. 50
C. 1
D.answer a and b

A

D.answer a and b

39
Q

104.In a darlington pair configuration, each transistor has an
ac beta of 125. If RE is 560 Ω, the input resistance is
A. 560 Ω B. 70 Ω
C. 140 kΩ D. 8.75 MΩ

A

D. 8.75 MΩ

40
Q

105.The input resistance of a common-base amplifier is
A. the same as a CC
B. the same as a CE
C. very low
D. very high

A

C. very low

41
Q

106.In a common-emitter amplifier with voltage-divider bias,
Rin(base) = 68 kΩ, R1 = 33 kΩ, and R2 = 15 kΩ. The total
input resistance is
A. 22.2 kΩ B. 68 kΩ
C. 8.95 kΩ D. 12.3 kΩ

A

C. 8.95 kΩ

42
Q

107.A CE amplifier is driving a 10 kΩ load. If RC = 2.2 kΩ and
r’e = 10 Ω, the voltage gain is approximately
A. 180 B. 220
C. 10 D. 1000

A

A. 180

43
Q

108.The overall gain found in Question 14 can be expressed
in decibels as
A. 47.0 dB B. 35.6 dB
C. 94.1 dB D. 69.8 dB

A

C. 94.1 dB

44
Q
A

ELEX (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions