Deck 17: RlC Circuits and Resonance

Question 1

To correctly bias a BJT, reverse-bias the base-emitter junction and forward-bias the base-collector
junction.

Answer 1

False

Question 2

Class C amplifiers are used primarily at radio frequencies.

Answer 2

True

Question 3

An enhancement-type MOSFET can operate with a positive value of VGS.

Answer 3

True

Question 4

A transistor can be used as an electronic switch.

Question 5

Voltage gain can be found by

Question 6

A BJT has three elements: emitter, gate, and collector.

Question 7

The overall voltage gain of a multistage amplifier is the product of the individual stage gains.

Question 8

The voltage gain of several amplifiers in series is found by adding the individual stage voltage
gains.

Question 9

If a common-emitter amplifier measures the same voltage on the collector as VCC, the amplifier is
operating in saturation.

Question 10

A current gain of almost one is a characteristic of a common-base amplifier.

Question 11

A depletion-type MOSFET can operate with a positive or negative value of VGS.

Question 12

The two types of BJTs are the PNP and the P-channel.

Question 13

The general characteristics of a common-emitter amplifier are high voltage gain, high current gain
and no phase reversal between the input and output voltages.

Question 14

The gate current in a JFET is normally zero.

Question 15

A common-collector amplifier has a high input impedance compared to a common-emitter 18)
amplifier.

Question 16

The two types of BJTs are the NPN and PNP.

Question 17

An amplifier that provides its own input is called an oscillator.

Question 18

Two types of FETs are the JFET and the MOSFET.

Question 19

The general characteristics of a common-emitter amplifier are low voltage gain, low current gain
and very high power gain.

Question 20

An N-channel JFET has three elements: source, gate, and drain.

Question 21

If equals 15 V in Figure 17-1, VBE equals ________.

A)15 V
B)0.7 V
C)5 V
D)4.71 V

Question 22

The amplifier in circuit Figure 17-2 uses a ________ and equals ________.

A)BJT, 10 V
B)TRIAC, 5 V
C)JFET, 10 V
D)JFET, 0 V

Question 23

Find in Figure 17-1.

A)11.4 V
B)16.4 V
C)7.10 V
D)6.4 V

Question 24

The device in Figure 17-2 is a ________.

A)NPN type BJT
B)P-channel MOSFET
C)N-channel JFET
D)depletion type MOSFET

Question 25

If the collector-to-emitter voltage is about 0 V in Figure 17-1, the possible trouble is ________.

A)the amplifier is saturated
B)the amplifier is cut off
C)this is a normal condition
D)the transistor is open

Question 26

If equals in Figure 17-1, the ________.

A)transistor is cutoff
B)emitter has opened
C)power is off
D)emitter is shorted to the collector

Question 27

Find in Figure 17-2.

A)-5 V
B)10 V
C)5 V
D)-10 V

Question 28

If opens in Figure 17-1, IC ________.

A)remains the same
B)decreases
C)increases
D)decreases to zero

Question 29

In all FETs, the drain current equals the ________ current.

A)emitter
B)collector
C)source
D)gate

Question 30

If opens in Figure 17-1, equals ________.

A)20 V
B)0.7 V
C)0 V
D)10 V

Question 31

If the emitter resistor opened in Figure 17-1, equals ________.

A)20 V
B)5.71 V
C)0.7 V
D)0 V

Question 32

If the base-emitter junction opened in Figure 17-1, equals ________.

A)20 V
B)0 V
C)10 V
D)5 V

Question 33

If mA in Figure 17-2, equals ________.

A)0 V
B)5 V
C)15 V
D)10 V

Question 34

The amplifier in Figure 17-2 uses a ________ and the gate current is ________.

A)TRIAC, 10 mA
B)JFET, 5 mA
C)JFET, 0 A
D)BJT, 0 A

Question 35

Find in Figure 17-2.

A)5 V
B)15 V
C)10 V
D)0 V

Question 36

If mA in Figure 17-2, equals ________.

A)15 V
B)25 V
C)0 V
D)-7.5 V

Question 37

If the BJTʹs collector opened internally in Figure 17-1, equals ________.

A)VBE
B)10 V
C)0 V
D)20 V

Question 38

Find in Figure 17-1.

A)0.7 V
B)5.71 V
C)5 V
D)15 V

Question 39

Which voltage might indicate that the amplifier in Figure 17-1 is cut off?

A)
B)
C)
D)

Question 40

If

A)The amplifier is saturated.
B)The amplifier is cut off.
C)The power is off.
D)This is normal.

Question 41

The Class B amplifier conducts for ________ of the input cycle.

A)a small portion
B)180°
C)only 10°
D)360°

Question 42

What is the total voltage gain of a three-stage amplifier that has stage gains of 22, 112, and 8?

A)19,712
B)142
C)1,420
D)197,120

Question 43

If a transistorʹs beta equals 30 and equals 1 mA, equals ________.

A)1 mA
B)30 mA
C)0.33 mA
D)unknown

Question 44

Which one of these characteristics is found in a common-collector amplifier?

A)a high input resistance
B)a very high power gain
C)a current gain of one
D)a low input resistance

Question 45

For normal operation of a NPN transistor, the base must be ________.

A)positive with respect to the collector
B)positive with respect to the emitter
C)negative with respect to the emitter
D)disconnected

Question 46

To analyze the operation of a BJT in an amplifier circuit, use characteristic curves of:

A)base current versus collector to emitter voltage.
B)emitter current versus emitter to collector voltage.
C)collector current versus emitter to collector voltage.
D)collector current versus collector to emitter voltage.

Question 47

On transistor spec sheet, the key difference between

A) represents represents
B) represents represents
C) represents represents
D) represents represents

Question 48

Although BJT transistors are current operated devices, a key characteristic is the signal voltage gain as an amplifier specified as:

A) .
B)
C)
D)

Question 49

To recognize transistor packages and identify the terminals, look for:

A)the flat side.
B)the imprinted dot.
C)the protruding tab.
D)all of these.

Question 50

The symbol in Figure 17-3(b) represents the ________.

A)N-channel depletion-type JFET
B)N-channel enhancement-type MOSFET
C)N-channel enhancement-type JFET
D)P-channel enhancement-type MOSFET

Question 51

The symbol in Figure 17-3(a) represents the ________.

A)N-channel enhancement-type JFET
B)N-channel enhancement-type MOSFET
C)P-channel enhancement-type MOSFET
D)N-channel depletion-type JFET

Question 52

If the base current increases, ________.

A)the collector current increases and the emitter current does not change
B)the collector current increases and the emitter current increases
C)the collector current increases and the emitter current decreases
D)the collector current decreases and the emitter current decreases

Question 53

In using BJT characteristic curves, the straight line drawn between the cutoff and the saturation points is called:

A)cutoff line.
B)load line.
C)saturation line.
D)operating line.

Question 54

Beta (β) is the ratio of ________.

A)collector current to base current
B)output voltage to input voltage
C)emitter current to base current
D)collector current to emitter current

Question 55

In all N-channel FETʹs, the current into the source equals the current leaving the ________.

A)source
B)drain
C)emitter
D)collector

Question 56

When a BJT amplifier is saturated, is about ________ and is ________.

A)zero, maximum
B)25 V, 10 mA
C)VCC, minimum
D)zero, minimum

Question 57

If a BJT amplifier is operated as a switch that is off, this operating condition is known as ________.

A)thermal runaway
B)VP
C)cutoff
D)saturation

Question 58

When a negative gate-to-source voltage is applied to an N-channel MOSFET, it operates ________.

A)in the enhancement mode
B)in the depletion mode
C)in the saturated state
D)in the cutoff state

Question 59

In using BJT characteristic curves, the intersection of the load line with a specific base current curve is called:

A)base point.
B)nudpoint.
C)Q point.
D)intersection point.

Question 60

What type of amplifier normally has a voltage gain of one?

A)common-mode
B)common-emitter
C)common-drain
D)common-source

Question 61

Which one of these amplifiers does NOT have the output in phase with the input?

A)common-drain
B)common-law
C)common-source
D)common-collector

Question 62

A Class ________ amplifier is very efficient.

A)C, audio
B)A, radio
C)C, radio
D)B, audio

Question 63

If the BJTʹs collector opens internally in Figure 17-4, ________.

A)drops almost to zero
B)increases
C)decreases
D)remains the same

Question 64

If the base-emitter junction opens in Figure 17-4, VC ________.

A)
B)
C)decreases to 0 volts
D)does not change

Question 65

If C1 opens in Figure 17-5, the circuit will probably ________.

A)increase its oscillating frequency
B)decrease its oscillating frequency
C)continue to operate normally
D)stop oscillating entirely

Question 66

If opens in Figure 17-4, VC equals ________.

A)9 V
B)18 V
C)VE
D)0 V

Question 67

If the collector opens in Figure 17-4, the output voltage ________.

A)decreases to zero
B)varies with temperature
C)increases
D)remains the same

Question 68

If RE opens in Figure 17-4, ________.

A)drops almost to zero
B)remains the same
C)increases
D)decreases

Question 69

Which voltage would indicate that the amplifier in Figure is operating in saturation?

A)
B) V
C) V
D)

Question 70

If the value of increases in Figure 17-5, the circuit ________.

A)operates at a higher frequency
B)operates at dc
C)operates at a lower frequency
D)does not change at all

Question 71

If the BJTʹs emitter internally shorted to its collector in Figure 17-4, ________.

A)decreases
B)remains the same
C)increases
D)drops almost to zero

Question 72

If C3 opens in Figure 17-4, ________.

A)the voltage gain decreases
B)the voltage gain increases
C)the dc emitter voltage decreases
D)the dc emitter voltage increases

Question 73

The circuit in Figure 17-5 is a ________ oscillator and uses ________ feedback.

A)Colpitts, positive
B)Colpitts, negative
C)crystal, negative
D)Hartley, positive

Question 74

The circuit in Figure 17-5 is known as a ________ oscillator because it has a ________ coil.

A)crystal, dual
B)Colpitts, dual
C)Hartley, dual

Question 75

Which one of these amplifiers has high input resistance and low output resistance?

A)common-cause
B)common-current
C)common-collector
D)common-emitter

Question 76

In Figure 17-5, form a ________ that provides ________ feedback to the amplifier.

A)tank circuit, negative
B)tank circuit, out-of-phase
C)feedback network, negative
D)tank circuit, positive

Question 77

If R1 shorts in Figure 17-4, ________.

A)
B)
C)
D)does not change

Question 78

Which voltage would enable the circuit in Figure 17-4 to operate with little distortion?

A)
B)
C)
D)

Question 79

Which voltage might allow the circuit in Figure 17-4 to operate with minimum distortion?

A)
B)
C)
D)

Question 80

Crossover distortion occurs in a ________ amplifier when the amplifier is biased at ________.

A)push-pull, cutoff
B)common-emitter, saturation
C)push-pull, saturation
D)common-source, cutoff