McqMate
| 1. |
A transistor has how many pn junctions? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| 2. |
In an npn transistor, the majority carriers in the emitter are |
| A. | free electrons |
| B. | holes |
| C. | neither |
| D. | both |
| Answer» A. free electrons | |
| 3. |
The barrier potential across each silicon depletion layer is |
| A. | 0v |
| B. | 0.3v |
| C. | 0.7v |
| D. | 1v |
| Answer» C. 0.7v | |
| 4. |
The base of an npn transistor is thin and |
| A. | heavily doped |
| B. | lightly doped |
| C. | metallic |
| D. | doped by a pentavalent material |
| Answer» B. lightly doped | |
| 5. |
The emitter of a transistor is generally doped the heaviest because it |
| A. | has to dissipate maximum power |
| B. | has to supply the charge carriers |
| C. | is the first region of the transistor |
| D. | must possess low resistance |
| Answer» A. has to dissipate maximum power | |
| 6. |
When a transistor is fully switched ON, it is said to be |
| A. | shorted |
| B. | saturated |
| C. | open |
| D. | cut-off |
| Answer» B. saturated | |
| 7. |
A FET consists of a |
| A. | source |
| B. | drain |
| C. | gate |
| D. | all the above |
| Answer» D. all the above | |
| 8. |
The extremely high input impedance of a MOSFET is primarily due to the |
| A. | absence of its channel |
| B. | negative gate- source voltage |
| C. | depletion of current carriers |
| D. | extremely small leakage current of its gate capacitor |
| Answer» D. extremely small leakage current of its gate capacitor | |
| 9. |
When a transistor is used as a switch, it is stable in which two distinct regions? |
| A. | saturation and active |
| B. | active and cutoff |
| C. | saturation and cutoff |
| D. | none of the above |
| Answer» C. saturation and cutoff | |
| 10. |
The term BJT is short for |
| A. | base junction transistor |
| B. | binary junction transistor |
| C. | both junction transistor |
| D. | bipolar junction transistor |
| Answer» D. bipolar junction transistor | |
| 11. |
What are the two types of bipolar junction transistors? |
| A. | npn and pnp |
| B. | pnn and nnp |
| C. | ppn and nnp |
| D. | pts and stp |
| Answer» A. npn and pnp | |
| 12. |
The magnitude of dark current in a phototransistor usually falls in what range? |
| A. | ma |
| B. | ma |
| C. | na |
| D. | pa |
| Answer» C. na | |
| 13. |
Junction Field Effect Transistors (JFET) contain how many diodes? |
| A. | 4 |
| B. | 3 |
| C. | 2 |
| D. | 1 |
| Answer» D. 1 | |
| 14. |
When not in use, MOSFET pins are kept at the same potential through the use of: |
| A. | shipping foil |
| B. | nonconductive foam |
| C. | conductive foam |
| D. | a wrist strap |
| Answer» C. conductive foam | |
| 15. |
A MOSFET has how many terminals? |
| A. | 2 or 3 |
| B. | 3 |
| C. | 4 |
| D. | 3 or 4 |
| Answer» D. 3 or 4 | |
| 16. |
A very simple bias for a D-MOSFET is called: |
| A. | self biasing |
| B. | gate biasing |
| C. | zero biasing |
| D. | voltage- divider biasing |
| Answer» C. zero biasing | |
| 17. |
Hybrid means |
| A. | mixed |
| B. | single |
| C. | biunique |
| D. | none of the above |
| Answer» A. mixed | |
| 18. |
There are h- parameters of a transistor. |
| A. | two |
| B. | four |
| C. | three |
| D. | none of the above |
| Answer» B. four | |
| 19. |
The h- parameter approach gives correct results for |
| A. | large signals only |
| B. | small signals only |
| C. | both small and large signals |
| D. | none of the above |
| Answer» B. small signals only | |
| 20. |
If the operating point changes, the h-parameters of transistor |
| A. | also change |
| B. | do not change |
| C. | may or may not change |
| D. | none of above |
| Answer» A. also change | |
| 21. |
The dc load line on a family of collector characteristic curves of a transistor shows the |
| A. | saturation region. |
| B. | cutoff region. |
| C. | active region. |
| D. | all of the above |
| Answer» D. all of the above | |
| 22. |
When a transistor is used as a switch, it is stable in which two distinct regions? |
| A. | saturation and active |
| B. | active and cutoff |
| C. | saturation and cutoff |
| D. | none of the above |
| Answer» C. saturation and cutoff | |
| 23. |
The value of βDC |
| A. | is fixed for any particular transistor. |
| B. | varies with temperature. |
| C. | varies with ic. |
| D. | varies with temperature and ic. |
| Answer» D. varies with temperature and ic. | |
| 24. |
A BJT has an IB of 50 µA and a βDC of 75; IC is: |
| A. | 375 ma |
| B. | 37.5 ma |
| C. | 3.75 ma |
| D. | 0.375 ma |
| Answer» C. 3.75 ma | |
| 25. |
A certain transistor has IC = 15 mA and IB = 167 µA; βDC is: |
| A. | 15 |
| B. | 167 |
| C. | 0.011 |
| D. | 90 |
| Answer» D. 90 | |
| 26. |
For normal operation of a pnp BJT, the base must be with respect to the emitter and with respect to the collector. |
| A. | positive, negative |
| B. | positive, positive |
| C. | negative, positive |
| D. | negative, negative |
| Answer» C. negative, positive | |
| 27. |
A transistor amplifier has a voltage gain of 100. If the input voltage is 75 mV, the output voltage is: |
| A. | 1.33 v |
| B. | 7.5 v |
| C. | 13.3 v |
| D. | 15 v |
| Answer» B. 7.5 v | |
| 28. |
A 35 mV signal is applied to the base of a properly biased transistor with an r'e = 8 Ω and RC = 1 kΩ. The output signal voltage at the collector is: |
| A. | 3.5 v |
| B. | 28.57 v |
| C. | 4.375 v |
| D. | 4.375 mv |
| Answer» C. 4.375 v | |
| 29. |
What is the order of doping, from heavily to lightly doped, for each region? |
| A. | base, collector, emitter |
| B. | emitter, collector, base |
| C. | emitter, base, collector |
| D. | collector, emitter, base |
| Answer» B. emitter, collector, base | |
| 30. |
Which of the following is true for an npn or pnp transistor? |
| A. | ie = ib + ic |
| B. | ib = ic+ ie |
| C. | ic = ib + ie |
| D. | none of the above |
| Answer» A. ie = ib + ic | |
| 31. |
In what range of voltages is the transistor in the linear region of its operation? |
| A. | 0 < vce |
| B. | 0.7 < vce < vce(max) |
| C. | vce(max) > vce |
| D. | none of the above |
| Answer» B. 0.7 < vce < vce(max) | |
| 32. |
What does DC vary with? |
| A. | ic |
| B. | ºc |
| C. | both ic and ºc |
| D. | ic’, but not ºc |
| Answer» C. both ic and ºc | |
| 33. |
What is (are) common fault(s) in a BJT-based circuit? |
| A. | pens or shorts internal to the transistor |
| B. | open bias resistor(s) |
| C. | external opens and shorts on the circuit board |
| D. | all of the above |
| Answer» D. all of the above | |
| 34. |
What is (are) general-purpose/small-signal transistors case type(s)? |
| A. | to-18 |
| B. | to-92 |
| C. | to-39 |
| D. | all of the above |
| Answer» D. all of the above | |
| 35. |
The magnitude of dark current in a phototransistor usually falls in what range? |
| A. | ma |
| B. | μa |
| C. | na |
| D. | pa |
| Answer» C. na | |
| 36. |
Which of the following devices has the highest input resistance? |
| A. | diode |
| B. | jfet |
| C. | mosfet |
| D. | bipolar junction transistor |
| Answer» C. mosfet | |
| 37. |
A self-biased n-channel JFET has a VD = 6 V. VGS = –3 V. Find the value of VDS. |
| A. | –3 v |
| B. | –6 v |
| C. | 3 v |
| D. | 6 v |
| Answer» B. –6 v | |
| 38. |
A JFET data sheet specifies VGS(off) = –6 V and IDSS = 8 mA. Find the value of ID when VGS = –3 V. |
| A. | 2 ma |
| B. | 4 ma |
| C. | 8 ma |
| D. | none of the above |
| Answer» A. 2 ma | |
| 39. |
A JFET data sheet specifies VGS(off) = –10 V and IDSS = 8 mA. Find the value of ID when VGS = –3 V. |
| A. | 2 ma |
| B. | 1.4 ma |
| C. | 4.8 ma |
| D. | 3.92 ma |
| Answer» D. 3.92 ma | |
| 40. |
The JFET is always operated with the gate-source pn junction -biased. |
| A. | forward |
| B. | reverse |
| C. | all of the above |
| D. | none of the above |
| Answer» B. reverse | |
| 41. |
What type(s) of gate-to-source voltage(s) can a depletion MOSFET (D-MOSFET) operate with? |
| A. | zero |
| B. | positive |
| C. | negative |
| D. | any of the above |
| Answer» D. any of the above | |
| 42. |
The has a physical channel between the drain and source. |
| A. | d-mosfet |
| B. | e-mosfet |
| C. | v-mosfet |
| D. | none of the above |
| Answer» A. d-mosfet | |
| 43. |
All MOSFETs are subject to damage from electrostatic discharge (ESD). |
| A. | true |
| B. | false |
| Answer» A. true | |
| 44. |
Midpoint bias for a D-MOSFET is ID = , obtained by setting VGS = 0. |
| A. | idss / 2 |
| B. | idss / 3.4 |
| C. | idss |
| Answer» C. idss | |
| 45. |
If VD is less than expected (normal) for a self-biased JFET circuit, then it could be caused by a(n) |
| A. | open rg. |
| B. | open gate lead. |
| C. | fet internally open at gate. |
| D. | all of the above |
| Answer» D. all of the above | |
| 46. |
A coupling capacitor is |
| A. | a dc short |
| B. | an ac open |
| C. | a dc open and an ac short |
| D. | a dc short and an ac open |
| Answer» C. a dc open and an ac short | |
| 47. |
In a bypass circuit, the top of a capacitor is |
| A. | an open |
| B. | a short |
| C. | an ac ground |
| D. | a mechanical ground |
| Answer» C. an ac ground | |
| 48. |
The capacitor that produces an ac ground is called a |
| A. | bypass capacitor |
| B. | coupling capacitor |
| C. | dc open |
| D. | ac open |
| Answer» A. bypass capacitor | |
| 49. |
The output voltage of a CE amplifier is |
| A. | amplified |
| B. | inverted |
| C. | 180° out of phase with the input |
| D. | all of the above |
| Answer» D. all of the above | |
| 50. |
A common-gate amplifier is similar in configuration to which BJT amplifier? |
| A. | common-emitter |
| B. | common- collector |
| C. | common-base |
| D. | emitter- follower |
| Answer» C. common-base | |
| 51. |
A common-source amplifier is similar in configuration to which BJT amplifier? |
| A. | common-base |
| B. | common- collector |
| C. | common-emitter |
| D. | emitter- follower |
| Answer» C. common-emitter | |
| 52. |
When transistors are used in digital circuits they usually operate in the |
| A. | active region |
| B. | breakdown region |
| C. | saturation and cutoff regions |
| D. | linear region |
| Answer» C. saturation and cutoff regions | |
| 53. |
Which of the following elements are important in determining the gain of the system in the high-frequency region? |
| A. | interelectrode capacitances |
| B. | wiring capacitances |
| C. | miller effect capacitance |
| D. | all of the above |
| Answer» D. all of the above | |
| 54. |
For audio systems, the reference level is generally accepted as . |
| A. | 1 mw |
| B. | 1 w |
| C. | 10 mw |
| D. | 100 mw |
| Answer» A. 1 mw | |
| 55. |
What is the normalized gain expressed in dB for the cutoff frequencies? |
| A. | –3 db |
| B. | +3 db |
| C. | –6 db |
| D. | –20 db |
| Answer» A. –3 db | |
| 56. |
Which of the following configurations does not involve the Miller effect capacitance? |
| A. | common-emitter |
| B. | common-base |
| C. | common- collector |
| D. | all of the above |
| Answer» B. common-base | |
| 57. |
When transistors are used in digital circuits they usually operate in the |
| A. | active region |
| B. | saturation and cutoff regions |
| C. | breakdown region |
| D. | linear region |
| Answer» B. saturation and cutoff regions | |
| 58. |
A current ratio of IC/IE is usually less than one and is called |
| A. | omega |
| B. | beta |
| C. | theta |
| D. | alpha |
| Answer» D. alpha | |
| 59. |
A transistor may be used as a switching device or as a: |
| A. | tuning device |
| B. | rectifier |
| C. | fixed resistor |
| D. | variable resistor |
| Answer» D. variable resistor | |
| 60. |
Most of the electrons in the base of an NPN transistor flow: |
| A. | into the collector |
| B. | into the emitter |
| C. | out of the base lead |
| D. | into the base supply |
| Answer» A. into the collector | |
| 61. |
The BJT is a device. The FET is a device. |
| A. | bipolar, bipolar |
| B. | bipolar, unipolar |
| C. | unipolar, bipolar |
| D. | unipolar, unipolar |
| Answer» B. bipolar, unipolar | |
| 62. |
The Bode plot is applicable to |
| A. | all phase network |
| B. | minimum phase network |
| C. | maximum phase network |
| D. | lag lead network |
| Answer» B. minimum phase network | |
| 63. |
For any inverting amplifier, the impedance capacitance will be by a Miller effect capacitance sensitive to the gain of the amplifier and the interelectrode capacitance. |
| A. | unaffected |
| B. | increased |
| C. | decreased |
| D. | none of the above |
| Answer» C. decreased | |
| 64. |
The dc emitter current of a transistor is 8 mA. What is the value of re? |
| A. | 320 Ω |
| B. | 13.3 kΩ |
| C. | 3.125 Ω |
| D. | 5.75 Ω |
| Answer» C. 3.125 Ω | |
| 65. |
An emitter-follower amplifier has an input impedance of 107 kΩ. 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» C. 12 mv | |
| 66. |
You have a need to apply an amplifier with a very high power gain. Which of the following would you choose? |
| A. | common-collector |
| B. | common-base |
| C. | common-emitter |
| D. | emitter- follower |
| Answer» C. common-emitter | |
| 67. |
What is the most important r parameter for amplifier analysis? |
| A. | rb′ |
| B. | rc′ |
| C. | re′ |
| D. | none of the above |
| Answer» C. re′ | |
| 68. |
A common-emitter amplifier has voltage gain, current gain, power gain, and input impedance. |
| A. | high, low, high, low |
| B. | high, high, high, low |
| C. | high, high, high, high |
| D. | low, low, low, high |
| Answer» B. high, high, high, low | |
| 69. |
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 vcc with ground |
| Answer» B. replace coupling and bypass capacitors with opens | |
| 70. |
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 |
| Answer» A. hre / hoe | |
| 71. |
The advantage that a Sziklai pair has over a Darlington pair is |
| A. | higher current gain. |
| B. | less input voltage is needed to turn it on. |
| C. | higher input impedance. |
| D. | higher voltage gain. |
| Answer» B. less input voltage is needed to turn it on. | |
| 72. |
What is the device in a transistor oscillator? |
| A. | lc tank circuit |
| B. | biasing circuit |
| C. | transistor |
| D. | feedback circuit |
| Answer» C. transistor | |
| 73. |
When the collector supply is 5V, then collector cut off voltage under dc condition is |
| A. | 20 v |
| B. | 10 v |
| C. | 2.5 v |
| D. | 5 v |
| Answer» D. 5 v | |
| 74. |
The common base (CB) amplifier has a compared to CE and CC amplifier. |
| A. | lower input resistance |
| B. | larger current gain |
| C. | larger voltage gain |
| D. | higher input resistance |
| Answer» A. lower input resistance | |
| 75. |
When a FET with a lower transconductance is substituted into a FET amplifier circuit, what happens? |
| A. | the current gain does not change |
| B. | the voltage gain decreases |
| C. | the circuit disamplifies |
| D. | the input resistance decreases |
| Answer» B. the voltage gain decreases | |
| 76. |
At zero signal condition, a transistor sees load. |
| A. | dc |
| B. | ac |
| C. | both dc and ac |
| D. | resistive |
| Answer» A. dc | |
| 77. |
What is the gain of an amplifier with negative feedback if the feedback factor is 0.01? |
| A. | 10 |
| B. | 1000 |
| C. | 100 |
| D. | 500 |
| Answer» C. 100 | |
| 78. |
The current gain of an emitter follower is |
| A. | equal to 1 |
| B. | greater than 1 |
| C. | less than 1 |
| D. | zero |
| Answer» C. less than 1 | |
| 79. |
The current in any branch of a transistor amplifier that is operating is |
| A. | ac only |
| B. | the sum of ac and dc |
| C. | the difference of ac and dc |
| D. | dc only |
| Answer» B. the sum of ac and dc | |
| 80. |
An ideal differential amplifiers common mode rejection ratio is |
| A. | infinite |
| B. | zero |
| C. | unity |
| D. | undetermined |
| Answer» A. infinite | |
| 81. |
An open fuse circuit has a resistance equal to |
| A. | zero |
| B. | unity |
| C. | at least 100Ω at standard |
| D. | infinity |
| Answer» D. infinity | |
| 82. |
What is the purpose of dc conditions in a transistor? |
| A. | to reverse bias the emitter |
| B. | to forward bias the emitter |
| C. | to set up operating point |
| D. | to turn on the transistor |
| Answer» C. to set up operating point | |
| 83. |
The ac variations at the output side of power supply circuits are called . |
| A. | ripples |
| B. | pulses |
| C. | waves |
| D. | filters |
| Answer» A. ripples | |
| 84. |
What is the purpose of the emitter capacitor? |
| A. | to forward bias the emitter |
| B. | to reduce noise in the amplifier |
| C. | to avoid drop in gain |
| D. | to stabilize emitter voltage |
| Answer» C. to avoid drop in gain | |
| 85. |
A common emitter circuit is also called circuit. |
| A. | grounded emitter |
| B. | grounded collector |
| C. | grounded base |
| D. | emitter follower |
| Answer» A. grounded emitter | |
| 86. |
The output signal of a common-collector amplifier is always |
| A. | larger than the input signal |
| B. | in phase with the input signal |
| C. | out of phase with the input signal |
| D. | exactly equal to the input signal |
| Answer» B. in phase with the input signal | |
| 87. |
Calculate the ripples of the filter output if a dc and ac voltmeter is used and measures the output signal from a filter circuit of 25 VDC and 1.5 Vrms |
| A. | 5% |
| B. | 10% |
| C. | 50% |
| D. | 6% |
| Answer» D. 6% | |
| 88. |
What is the ideal maximum voltage gain of a common collector amplifier? |
| A. | unity |
| B. | infinite |
| C. | indeterminate |
| D. | zero |
| Answer» A. unity | |
| 89. |
The output power of a transistor amplifier is more than the input power due to additional power supplied by |
| A. | transistor |
| B. | collector supply |
| C. | emitter supply |
| D. | base supply |
| Answer» B. collector supply | |
| 90. |
When a transistor amplifier feeds a load of low resistance, its voltage gain will be |
| A. | low |
| B. | very high |
| C. | high |
| D. | moderate |
| Answer» A. low | |
| 91. |
The capacitors are considered in the ac equivalent circuit of a transistor amplifier. |
| A. | open |
| B. | partially open |
| C. | short |
| D. | partially short |
| Answer» C. short | |
| 92. |
For highest power gain, what configuration is used? |
| A. | cc |
| B. | cb |
| C. | ce |
| D. | cs |
| Answer» C. ce | |
| 93. |
What is the most important characteristic of a common collector amplifier? |
| A. | high input voltage |
| B. | high input resistance |
| C. | high output resistance |
| D. | its being an amplifier circuit |
| Answer» B. high input resistance | |
| 94. |
Which of the item below does not describe a common emitter amplifier? |
| A. | high voltage gain |
| B. | high current gain |
| C. | very high power gain |
| D. | high input resistance |
| Answer» D. high input resistance | |
| 95. |
CC configuration is used for impedance matching because its |
| A. | input impedance is very high |
| B. | input impedance is very low |
| C. | output impedance is very low |
| D. | output impedance is zero |
| Answer» A. input impedance is very high | |
| 96. |
Which of the following is the other name of the output stage in an amplifier? |
| A. | load stage |
| B. | audio stage |
| C. | power stage |
| D. | rf stage |
| Answer» C. power stage | |
| 97. |
When amplifiers are cascaded |
| A. | the gain of each amplifier is increased |
| B. | a lower supply voltage is required |
| C. | the overall gain is increased |
| D. | each amplifier has to work less |
| Answer» C. the overall gain is increased | |
| 98. |
Ina common emitter amplifier, the capacitor from emitter to ground is called the |
| A. | coupling capacitor |
| B. | bypass capacitor |
| C. | decoupling capacitor |
| D. | tuning capacitor |
| Answer» B. bypass capacitor | |
| 99. |
A class A power amplifier uses transistor(s). |
| A. | two |
| B. | one |
| C. | three |
| D. | four |
| Answer» B. one | |
| 100. |
What is the maximum collector efficiency of a resistance loaded class A power amplifier? |
| A. | 50% |
| B. | 78.50% |
| C. | 25% |
| D. | 30% |
| Answer» C. 25% | |
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