Question 1

Emitter-feedback and collector-feedback bias circuits are inadequate because

Accepted Answer

A)  there is not enough negative feedback. 
B)  there is too much negative feedback. 
C)  circuits are too complex. 
D)  there is not enough positive feedback. 
A)  there is not enough negative feedback. 
B)  there is too much negative feedback. 
C)  circuits are too complex. 
D)  there is not enough positive feedback.

Question 2

The emitter-base junction voltage of the silicon transistor shown in Figure 7-12 is approximated to be 0.3 V.

Accepted Answer

A) True 
 B)False

Question 3

In Figure 7-5,when the fuse is not blown

Accepted Answer

A)  the transistor is biased on and the green LED illuminates. 
B)  the transistor is biased off and the green LED illuminates. 
C)  the transistor is biased on and the red LED illuminates. 
D)  the transistor is biased off and the red LED illuminates. 
A)  the transistor is biased on and the green LED illuminates. 
B)  the transistor is biased off and the green LED illuminates. 
C)  the transistor is biased on and the red LED illuminates. 
D)  the transistor is biased off and the red LED illuminates.

Question 4

Emitter bias is used to stabilize the Q point on the load line against current gain changes.

Accepted Answer

A) True 
 B)False

Question 5

Emitter-feedback bias has never become popular because the movement of the Q point is

Accepted Answer

A)  stationary at cutoff. 
B)  stationary at saturation. 
C)  too large for applications that must be mass-produced. 
D)  too small for applications that must be mass-produced. 
A)  stationary at cutoff. 
B)  stationary at saturation. 
C)  too large for applications that must be mass-produced. 
D)  too small for applications that must be mass-produced.

Question 6

In the circuit shown in Figure 7-12,the first step in finding the emitter current is to determine the voltage across R2.

Accepted Answer

A) True 
 B)False

Question 7

In Figure 7-18,the positive supply

Accepted Answer

A)  forward-biases the collector diode. 
B)  reverse-biases the collector diode. 
C)  forward-biases the emitter diode. 
D)  reverse-biases the emitter diode. 
A)  forward-biases the collector diode. 
B)  reverse-biases the collector diode. 
C)  forward-biases the emitter diode. 
D)  reverse-biases the emitter diode.

Question 8

Some electronic equipment has a power supply that produces both positive and negative supply voltages.

Accepted Answer

A) True 
 B)False

Question 9

Emitter-feedback and collector-feedback are typically not adequate because

Accepted Answer

A)  there is too much negative feedback. 
B)  there is not enough negative feedback. 
C)  circuitry is too complex. 
D)  there is not enough positive feedback. 
A)  there is too much negative feedback. 
B)  there is not enough negative feedback. 
C)  circuitry is too complex. 
D)  there is not enough positive feedback.

Question 10

Collector-feedback bias is more effective than emitter-feedback bias and is used in practice because of its

Accepted Answer

A)  ability to change current gain. 
B)  low cost. 
C)  simplicity. 
D)  small size. 
A)  ability to change current gain. 
B)  low cost. 
C)  simplicity. 
D)  small size.

Question 11

If RE is adjusted it its minimum value in Figure 7-16,the Q point moves toward cut-off.

Accepted Answer

A) True 
 B)False

Question 12

What type transistor is used when the electronics equipment has a negative power supply?

Accepted Answer

A)  field effect 
B)  small-signal 
C)  npn 
D)  pnp 
A)  field effect 
B)  small-signal 
C)  npn 
D)  pnp

Question 13

Emitter-feedback bias is also called self-bias.

Accepted Answer

A) True 
 B)False

Question 14

The voltage measured across the base-emitter junction of the silicon transistor shown in Figure 7-29 (a)is ________.

Accepted Answer

A)  0.3 V 
B)  1.3 V 
C)  0.7 V 
D)  1.7 V 
A)  0.3 V 
B)  1.3 V 
C)  0.7 V 
D)  1.7 V

Question 15

Emitter-feedback bias uses a resistor that provides negative feedback in attempt to stabilize the operating point.

Accepted Answer

A) True 
 B)False

Question 16

The most widely used transistor biasing circuit is called

Accepted Answer

A)  negative bias. 
B)  voltage-multiplier bias. 
C)  voltage-divider bias. 
D)  full-wave bridge bias. 
A)  negative bias. 
B)  voltage-multiplier bias. 
C)  voltage-divider bias. 
D)  full-wave bridge bias.

Question 17

The main advantage of an optocoupler is

Accepted Answer

A)  electrical isolation between input and output circuits. 
B)  electrical connection between input and output circuits. 
C)  inexpensive manufacturing costs. 
D)  miniature size. 
A)  electrical isolation between input and output circuits. 
B)  electrical connection between input and output circuits. 
C)  inexpensive manufacturing costs. 
D)  miniature size.

Question 18

With a pnp transistor,the base-emitter junction will be forward biased

Accepted Answer

A)  when the emitter voltage is 0.7 V above the base voltage. 
B)  when the emitter voltage is 0.7 V below the base voltage. 
C)  when the transistor is in cut-off. 
D)  when the collector voltage is 0.7 V above the base voltage. 
A)  when the emitter voltage is 0.7 V above the base voltage. 
B)  when the emitter voltage is 0.7 V below the base voltage. 
C)  when the transistor is in cut-off. 
D)  when the collector voltage is 0.7 V above the base voltage.

Question 19

By exposing a transistor's collector junction to light,a manufacturer can produce

Accepted Answer

A)  an LED. 
B)  a seven-segment display. 
C)  a common-emitter circuit. 
D)  a phototransistor. 
A)  an LED. 
B)  a seven-segment display. 
C)  a common-emitter circuit. 
D)  a phototransistor.

Question 20

In the circuit shown in Figure 7-26,if the base voltage measured 0 V and the emitter voltage measured 0 V,what should the troubleshooter do?

Accepted Answer

A)  replace the transistor 
B)  replace RE 
C)  check R1 
D)  check voltage source and leads 
A)  replace the transistor 
B)  replace RE 
C)  check R1 
D)  check voltage source and leads

Exam 7: BJT Biasing

Emitter-feedback and collector-feedback bias circuits are inadequate because

The emitter-base junction voltage of the silicon transistor shown in Figure 7-12 is approximated to be 0.3 V.

In Figure 7-5,when the fuse is not blown

Emitter bias is used to stabilize the Q point on the load line against current gain changes.

Emitter-feedback bias has never become popular because the movement of the Q point is

In the circuit shown in Figure 7-12,the first step in finding the emitter current is to determine the voltage across R2.

In Figure 7-18,the positive supply

Some electronic equipment has a power supply that produces both positive and negative supply voltages.

Emitter-feedback and collector-feedback are typically not adequate because

Collector-feedback bias is more effective than emitter-feedback bias and is used in practice because of its

If RE is adjusted it its minimum value in Figure 7-16,the Q point moves toward cut-off.

What type transistor is used when the electronics equipment has a negative power supply?

Emitter-feedback bias is also called self-bias.

The voltage measured across the base-emitter junction of the silicon transistor shown in Figure 7-29 (a)is ________.

Emitter-feedback bias uses a resistor that provides negative feedback in attempt to stabilize the operating point.

The most widely used transistor biasing circuit is called

The main advantage of an optocoupler is

With a pnp transistor,the base-emitter junction will be forward biased

By exposing a transistor's collector junction to light,a manufacturer can produce

In the circuit shown in Figure 7-26,if the base voltage measured 0 V and the emitter voltage measured 0 V,what should the troubleshooter do?

Introduction

Semoconductors

Diode Theory Key

Diode Circuits

Special-Purpose Diodes Key

BJT Fumdamentals

Basic BJT Amplifiers

Multistage,CC,and CB Amplifiers

Power Amplifiers

JFETS

Mosfets

Thyristors

Frequency Effects

Differential Amplifiers

Operational Amplifiers

Negative Feedback

Linear OP AMP Circuits

Active Filters Key

Nonlinear Op-Amp Circuit Applications Key

Oscillators Key

Regulated Power Supplies Key

Filters

In the circuit shown in Figure 7-12,the first step in finding the emitter current is to determine the voltage across R₂.

If R_E is adjusted it its minimum value in Figure 7-16,the Q point moves toward cut-off.