MCQOPTIONS
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MCQOPTIONS
This section includes 131 Mcqs, each offering curated multiple-choice questions to sharpen your Active Filter Circuits knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The output resistance of the common-emitter amplifier is approximately equal to the collector resistance. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 52. |
The total voltage gain of a multistage amplifier is the product of the individual stage gains. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 53. |
Besides the fact that DC = IC/IB and ac = IC/IB, these quantities are always the same for purposes of small-signal amplification. |
| A. | True |
| B. | False |
| Answer» C. | |
| 54. |
A Darlington pair provides a very low input impedance. |
| A. | True |
| B. | False |
| Answer» C. | |
| 55. |
A common-emitter amplifier has the advantages of good voltage, current, and power gain, but the disadvantage of a relatively low input impedance. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 56. |
What is re equal to in terms of h parameters? |
| A. | hre / hoe |
| B. | (hre + 1) / hoe |
| C. | hie – (hre / hoe)(1 + hfe) |
| D. | hfe |
| E. | none of the above |
| Answer» B. (hre + 1) / hoe | |
| 57. |
The total gain of a multistage amplifier is the ________. |
| A. | sum of individual voltage gains |
| B. | sum of dB voltage gains |
| Answer» C. | |
| 58. |
Refer to this figure. You notice while servicing this amplifier that the output signal at Vout is reduced from normal. The problem could be caused by |
| A. | an open C3. |
| B. | an open C2. |
| C. | an open base-emitter of Q2. |
| D. | a shorted C2. |
| Answer» C. an open base-emitter of Q2. | |
| 59. |
An emitter-follower amplifier has an input impedance of 107 k. The input signal is 12 mV. The approximate output voltage is (common-collector) |
| A. | 8.92 V |
| B. | 112 mV |
| C. | 12 mV |
| D. | 8.9 mV |
| Answer» D. 8.9 mV | |
| 60. |
Refer to this figure. If an emitter bypass capacitor was installed, what would the new Av be? |
| A. | 4.96 |
| B. | 125 |
| C. | 398 |
| D. | 600 |
| Answer» E. | |
| 61. |
Refer to this figure. If an emitter bypass capacitor was installed, determine the value of Rin(base). |
| A. | 416 |
| B. | 5 k |
| C. | 50 k |
| D. | 500 |
| Answer» B. 5 k | |
| 62. |
Refer to this figure. Calculate the value of Rin(tot). |
| A. | 37.7 k |
| B. | 3.77 k |
| C. | 378 |
| D. | 2.25 k |
| Answer» C. 378 | |
| 63. |
Refer to this figure. Determine the value of Av. |
| A. | 49.6 |
| B. | 5 |
| C. | 100 |
| D. | 595 |
| Answer» C. 100 | |
| 64. |
Refer to this figure. Find the value of Rin(base). |
| A. | 420 |
| B. | 50 k |
| C. | 940 |
| D. | 100.8 |
| Answer» C. 940 | |
| 65. |
Refer to this figure. Determine the value of VC. |
| A. | 20 V |
| B. | 10 V |
| C. | 5 V |
| D. | 0 V |
| Answer» D. 0 V | |
| 66. |
Refer to this figure. Find the value of IE. |
| A. | 2 mA |
| B. | 4 mA |
| C. | 5 mA |
| D. | 6 mA |
| Answer» E. | |
| 67. |
Refer to this figure. Calculate the value of VB. |
| A. | 5 V |
| B. | 3.7 V |
| C. | 20 V |
| D. | 3 V |
| Answer» C. 20 V | |
| 68. |
The dc emitter current of a transistor is 8 mA. What is the value of re? |
| A. | 320 |
| B. | 13.3 k |
| C. | 3.125 |
| D. | 5.75 |
| Answer» D. 5.75 | |
| 69. |
The loaded voltage gain of an amplifier is always more than the no-load level. |
| A. | True |
| B. | False |
| C. | - |
| D. | - |
| Answer» C. - | |
| 70. |
A Darlington pair amplifier has |
| A. | high input impedance and high voltage gain. |
| B. | low input impedance and low voltage gain. |
| C. | a voltage gain of about 1 and a low input impedance. |
| D. | a low voltage gain and a high input impedance. |
| Answer» E. | |
| 71. |
A Darlington pair provides beta ________ for ________ input resistance. |
| A. | multiplication, decreased |
| B. | multiplication, increased |
| C. | division, decreased |
| D. | - |
| Answer» C. division, decreased | |
| 72. |
Refer to this figure. If an emitter bypass capacitor was installed, what would the new A v be? |
| A. | 4.96 |
| B. | 125 |
| C. | 398 |
| D. | 600 |
| Answer» E. | |
| 73. |
The ________ the source resistance and/or ________ the load resistance, the less the overall gain of an amplifier. |
| A. | smaller, smaller |
| B. | smaller, larger |
| C. | larger, smaller |
| D. | larger, larger |
| Answer» D. larger, larger | |
| 74. |
The input impedance of a BJT amplifier is purely ________ in nature and can vary from a few ________ to ________. |
| A. | resistive, ohms, megohms |
| B. | capacitive, microfarads, farads |
| C. | inductive, millihenrys, henrys |
| D. | None of the above |
| Answer» B. capacitive, microfarads, farads | |
| 75. |
Which of the following techniques can be used in the sinusoidal ac analysis of transistor networks? |
| A. | Small-signal |
| B. | Large-signal |
| C. | Small- or large-signal |
| D. | None of the above |
| Answer» D. None of the above | |
| 76. |
What is r e equal to in terms of h parameters? |
| A. | h re / h oe |
| B. | (h re + 1) / h oe |
| C. | h ie – (h re / h oe )(1 + h fe ) |
| D. | h fe |
| Answer» B. (h re + 1) / h oe | |
| 77. |
What is the controlling current in a common-base configuration? |
| A. | I e |
| B. | I c |
| C. | I b |
| D. | None of the above |
| Answer» B. I c | |
| 78. |
What is the limit of the efficiency defined by = P o / P i ? |
| A. | Greater than 1 |
| B. | Less than 1 |
| C. | Always 1 |
| D. | None of the above |
| Answer» C. Always 1 | |
| 79. |
Refer to this figure. The output signal from the first stage of this amplifier is 0 V. The trouble could be caused by |
| A. | an open C 4 . |
| B. | an open C 2 . |
| C. | an open base-emitter of Q 1 . |
| D. | a shorted C 4 . |
| Answer» D. a shorted C 4 . | |
| 80. |
Which of the following is (are) true regarding the output impedance for frequencies in the midrange 100 kHz of a BJT transistor amplifier? |
| A. | The output impedance is purely resistive. |
| B. | It varies from a few ohms to more than 2 M . |
| C. | An ohmmeter cannot be used to measure the small-signal ac output impedance. |
| D. | All of the above |
| Answer» E. | |
| 81. |
An emitter-follower amplifier has an input impedance of 107 k . The input signal is 12 mV. The approximate output voltage is (common-collector) |
| A. | 8.92 V |
| B. | 112 mV |
| C. | 12 mV |
| D. | 8.9 mV |
| Answer» D. 8.9 mV | |
| 82. |
Which of the following configurations has a voltage gain of –R C /r e ? |
| A. | Fixed-bias common-emitter |
| B. | Common-emitter voltage-divider with bypass capacitor |
| C. | Fixed-bias common-emitter and voltage-divider with bypass capacitor |
| D. | Common-emitter voltage-divider without bypass capacitor |
| Answer» D. Common-emitter voltage-divider without bypass capacitor | |
| 83. |
For BJT amplifiers, the ________ gain typically ranges from a level just less than 1 to a level that may exceed 1000. |
| A. | voltage |
| B. | current |
| C. | impedance |
| D. | All of the above |
| Answer» C. impedance | |
| 84. |
For a common-emitter amplifier, the purpose of the emitter bypass capacitor is |
| A. | no purpose, since it is shorted out by R E . |
| B. | to reduce noise. |
| C. | to despike the supply voltage. |
| D. | to maximize amplifier gain. |
| Answer» E. | |
| 85. |
Refer to this figure. Find the value of R in(base) . |
| A. | 420 |
| B. | 50 k |
| C. | 940 |
| D. | 100.8 |
| Answer» C. 940 | |
| 86. |
Which of the following configurations has an output impedance Z o equal to R C ? |
| A. | Fixed-bias common-emitter |
| B. | Common-emitter voltage-divider with bypass capacitor |
| C. | Common-emitter voltage-divider without bypass capacitor |
| D. | All of the above |
| Answer» E. | |
| 87. |
A common-collector amplifier has ________ input resistance, ________ current gain, and ________ voltage gain. |
| A. | high, high, low |
| B. | high, low, low |
| C. | high, low, high |
| D. | - |
| Answer» B. high, low, low | |
| 88. |
For the collector dc feedback configuration, there is a ________ phase shift between the input and output signals. |
| A. | 0º |
| B. | 45º |
| C. | 90º |
| D. | 180º |
| Answer» E. | |
| 89. |
Which of the following is (are) true regarding the input impedance for frequencies in the midrange 100 kHz of a BJT transistor amplifier? |
| A. | The input impedance is purely resistive. |
| B. | It varies from a few ohms to megohms. |
| C. | An ohmmeter cannot be used to measure the small-signal ac input impedance. |
| D. | All of the above |
| Answer» E. | |
| 90. |
Which of the following should be done to obtain the ac equivalent of a network? |
| A. | Set all dc sources to zero |
| B. | Replace all capacitors by a short-circuit equivalent. |
| C. | Remove all elements bypassed by the short-circuit equivalent. |
| D. | All of the above |
| Answer» E. | |
| 91. |
The dc emitter current of a transistor is 8 mA. What is the value of r e ? |
| A. | 320 |
| B. | 13.3 k |
| C. | 3.125 |
| D. | 5.75 |
| Answer» D. 5.75 | |
| 92. |
Which of the following define(s) the conversion efficiency? |
| A. | Ac power to the load/ac input power |
| B. | Ac power to the load/dc power supplied |
| C. | Dc output power/ac input power |
| D. | All of the above |
| Answer» C. Dc output power/ac input power | |
| 93. |
Under which of the following conditions is the output impedance of the network approximately equal to R C for a common-emitter fixed-bias configuration? |
| A. | r o 10R C |
| B. | r o < 10R C |
| C. | r o < r o |
| D. | r o > r o |
| Answer» B. r o < 10R C | |
| 94. |
Which of the following gains is less than 1 for a common-base configuration? |
| A. | A i |
| B. | A v |
| C. | A p |
| D. | None of the above |
| Answer» B. A v | |
| 95. |
Refer to this figure. If an emitter bypass capacitor was installed, determine the value of R in(base) . |
| A. | 416 |
| B. | 5 k |
| C. | 50 k |
| D. | 500 |
| Answer» B. 5 k | |
| 96. |
For the common-emitter amplifier ac equivalent circuit, all capacitors are |
| A. | effectively shorts. |
| B. | effectively open circuits. |
| C. | not connected to ground. |
| D. | connected to ground. |
| Answer» B. effectively open circuits. | |
| 97. |
To analyze the common-emitter amplifier, what must be done to determine the dc equivalent circuit? |
| A. | leave circuit unchanged |
| B. | replace coupling and bypass capacitors with opens |
| C. | replace coupling and bypass capacitors with shorts |
| D. | replace V CC with ground |
| Answer» C. replace coupling and bypass capacitors with shorts | |
| 98. |
Which of the following is (are) true to achieve a good overall voltage gain for the circuit? |
| A. | The effect of R s and R L must be considered as a product. |
| B. | The effect of R s and R L must be considered as a product and evaluated individually. |
| C. | The effect of R s and R L must be evaluated individually. |
| D. | None of the above |
| Answer» C. The effect of R s and R L must be evaluated individually. | |
| 99. |
In a common-base amplifier, the input signal is connected to the |
| A. | base. |
| B. | collector. |
| C. | emitter. |
| D. | output. |
| Answer» D. output. | |
| 100. |
Refer to this figure. Determine the value of V C . |
| A. | 20 V |
| B. | 10 V |
| C. | 5 V |
| D. | 0 V |
| Answer» D. 0 V | |