MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 98 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
A diode for which you can change the reverse bias, and thus vary the capacitance is called a |
| A. | varactor diode |
| B. | tunnel diode |
| C. | zener diode |
| D. | switching diode |
| Answer» B. tunnel diode | |
| 52. |
At any given time in an intrinsic piece of semiconductor material at room temperature |
| A. | electrons drift randomly |
| B. | recombination occurs |
| C. | holes are created |
| D. | All of the above |
| Answer» E. | |
| 53. |
If the diode in a series circuit is reverse biased, the resistor will drop all the applied voltage. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 54. |
In a power supply diagram, which block indicates a smooth dc output? |
| A. | transformer |
| B. | filter |
| C. | rectifier |
| D. | regulator |
| Answer» E. | |
| 55. |
The voltage where current may start to flow in a reverse-biased pn junction is called the |
| A. | breakdown voltage |
| B. | barrier potential |
| C. | forward voltage |
| D. | biasing voltage |
| Answer» B. barrier potential | |
| 56. |
The average value of the half-wave rectified output voltage is approximately __________ of Vp. |
| A. | 0.318 |
| B. | 0.636 |
| C. | 0.707 |
| D. | 1 |
| Answer» B. 0.636 | |
| 57. |
An IC regulator receives an overload; it will: |
| A. | shut down |
| B. | compensate for heat |
| C. | provide more voltage |
| D. | sample and adjust |
| Answer» B. compensate for heat | |
| 58. |
The troubleshooting process for a typical dc power supply contains four steps. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 59. |
When a diode is destroyed it has infinite impedance. When damaged by heat it will probably: |
| A. | short |
| B. | conduct more |
| C. | conduct less |
| D. | open |
| Answer» B. conduct more | |
| 60. |
The arrow in the schematic symbol of a diode points to |
| A. | the n-type material, which is called the anode |
| B. | the n-type material, which is called the cathode |
| C. | the p-type material, which is called the anode |
| D. | the p-type material, which is called the cathode |
| Answer» D. the p-type material, which is called the cathode | |
| 61. |
The positive lead of a diode is the cathode. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» C. 1 | |
| 62. |
Which of the following circuits would require the least amount of filtering? |
| A. | A half-wave rectifier |
| B. | A full-wave rectifier |
| C. | A bridge rectifier |
| D. | A full-wave rectifier and a bridge rectifier |
| Answer» E. | |
| 63. |
Electrons in the outermost orbit or shell of an atom are called |
| A. | free electrons |
| B. | negative ions |
| C. | valence electrons |
| D. | conduction band electrons |
| Answer» D. conduction band electrons | |
| 64. |
List three diode packages: |
| A. | clip package, DIP, small current package |
| B. | DIP, small current package, large current package |
| C. | small current package, large current package, and SIP |
| D. | small current package, large current package, clip package |
| Answer» E. | |
| 65. |
A pn junction allows current flow when |
| A. | the p-type material is more positive than the n-type material |
| B. | the n-type material is more positive than the p-type material |
| C. | both the n-type and p-type materials have the same potential |
| D. | there is no potential on the n-type or p-type materials |
| Answer» B. the n-type material is more positive than the p-type material | |
| 66. |
The name of the circuit in the given circuit is the ___. |
| A. | half-wave rectifier |
| B. | center-tapped full-wave rectifier |
| C. | full-wave bridge rectifier |
| D. | half-wave bridge rectifier |
| Answer» D. half-wave bridge rectifier | |
| 67. |
If a 169.7 V half-wave peak has an average voltage of 54 V, what is the average of two full-wave peaks? |
| A. | 119.9 V |
| B. | 108.0 V |
| C. | 115.7 V |
| D. | 339.4 V |
| Answer» C. 115.7 V | |
| 68. |
A characteristic curve is the result of a current versus voltage plot of diode activity, which begins at the: |
| A. | 3rd quadrant |
| B. | current plot |
| C. | graph origin |
| D. | voltage plot |
| Answer» D. voltage plot | |
| 69. |
With full-wave rectification, current through the load resistor must be: |
| A. | in opposite directions |
| B. | to the external load |
| C. | from the reverse biased diode |
| D. | in the same direction |
| Answer» E. | |
| 70. |
The mimicking of an open/closed switch by a diode allows alternating current to be: |
| A. | rectified |
| B. | regulated |
| C. | controlled |
| D. | attenuated |
| Answer» B. regulated | |
| 71. |
What is the current through the LED? |
| A. | 0 mA |
| B. | 23 mA |
| C. | 18 mA |
| D. | 13 mA |
| Answer» E. | |
| 72. |
A rectifying diode can change ac voltage to dc voltage. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 73. |
If the frequency of the applied ac signal to a half-wave rectifier is 60 Hz, the frequency of the pulsating dc output will be |
| A. | 30 pps |
| B. | 60 pps |
| C. | 90 pps |
| D. | 120 pps |
| Answer» C. 90 pps | |
| 74. |
The diode schematic arrow points to the: |
| A. | trivalent-doped material |
| B. | positive axial lead |
| C. | anode lead |
| D. | cathode lead |
| Answer» E. | |
| 75. |
A filtered full-wave rectifier voltage has a smaller ripple than does a half-wave rectifier voltage for the same load resistance and capacitor values because: |
| A. | there is a shorter time between peaks |
| B. | there is a longer time between peaks |
| C. | the larger the ripple, the better the filtering action |
| D. | none of the above |
| Answer» B. there is a longer time between peaks | |
| 76. |
The area at the junction of p-type and n-type materials that has lost its majority carriers is called the |
| A. | barrier potential |
| B. | depletion region |
| C. | n region |
| D. | p region |
| Answer» C. n region | |
| 77. |
The small amount of ac signal present on the output of a filtering network for a dc power supply is known as ________. |
| A. | pulsating dc |
| B. | trickle |
| C. | ripple |
| D. | waffle |
| Answer» D. waffle | |
| 78. |
Typically the forward voltage on an LED is between _______ and ________. |
| A. | 1.5 V, 3.7 V |
| B. | 0.7 V, 1.1 V |
| C. | 1 V, 3 V |
| D. | 1 V, 6 V |
| Answer» D. 1 V, 6 V | |
| 79. |
Why is heat produced in a diode? |
| A. | due to current passing through the diode |
| B. | due to voltage across the diode |
| C. | due to the power rating of the diode |
| D. | due to the PN junction of the diode |
| Answer» B. due to voltage across the diode | |
| 80. |
What is wrong with this circuit? |
| A. | The zener is open. |
| B. | The zener is shorted. |
| C. | nothing |
| D. | not enough data |
| Answer» B. The zener is shorted. | |
| 81. |
With a half-wave rectified voltage across the load resistor, load current flows for what part of a cycle? |
| A. | 0 degrees |
| B. | 90 degrees |
| C. | 180 degrees |
| D. | 360 degrees |
| Answer» D. 360 degrees | |
| 82. |
Testing a good diode with an ohmmeter should indicate |
| A. | high resistance when forward or reverse biased |
| B. | low resistance when forward or reverse biased |
| C. | high resistance when reverse biased and low resistance when forward biased |
| D. | high resistance when forward biased and low resistance when reverse biased |
| Answer» D. high resistance when forward biased and low resistance when reverse biased | |
| 83. |
When matching polarity connections have been made and the potential difference (PD) is above 0.7 V, the diode is considered to be: |
| A. | not working |
| B. | forward biased |
| C. | reverse biased |
| D. | an open switch |
| Answer» C. reverse biased | |
| 84. |
In a diode schematic, the anode is represented by a(n): |
| A. | triangle |
| B. | vertical line |
| C. | zig-zag line |
| D. | element indicator |
| Answer» B. vertical line | |
| 85. |
What circuit activity may shift a characteristic curve so that diode operating points are different? |
| A. | higher power (heat) |
| B. | higher resistance |
| C. | lower voltage |
| D. | lower current |
| Answer» B. higher resistance | |
| 86. |
What is wrong with this diode? |
| A. | open |
| B. | short |
| C. | nothing |
| D. | not enough data |
| Answer» D. not enough data | |
| 87. |
When a diode is forward biased, the voltage across it |
| A. | is directly proportional to the current |
| B. | is inversely proportional to the current |
| C. | is directly proportional to the source voltage |
| D. | remains approximately the same |
| Answer» E. | |
| 88. |
Providing a constant output regardless of ac input or load resistance changes is the function of a: |
| A. | transformer |
| B. | filter |
| C. | regulator |
| D. | rectifier |
| Answer» D. rectifier | |
| 89. |
A ___ is created when an electron moves from the valence band to the conduction band. |
| A. | hole |
| B. | gap |
| C. | vacancy |
| D. | blank |
| Answer» B. gap | |
| 90. |
What is the current through the diode? |
| A. | 1 mA |
| B. | 0.975 mA |
| C. | 0.942 mA |
| D. | 0.0 mA |
| Answer» B. 0.975 mA | |
| 91. |
The dc current through each diode in a bridge rectifier equals: |
| A. | the load current |
| B. | half the dc load current |
| C. | twice the dc load current |
| D. | one-fourth the dc load current |
| Answer» B. half the dc load current | |
| 92. |
What is the percent of regulation if Vnl = 20 V and Vfl = 19.8 V? |
| A. | 0 |
| B. | 0.01 |
| C. | 0.001 |
| D. | 0.05 |
| Answer» C. 0.001 | |
| 93. |
In a power supply diagram, which block indicates a pulsating dc output? |
| A. | transformer |
| B. | filter |
| C. | rectifier |
| D. | regulator |
| Answer» D. regulator | |
| 94. |
Which type of transformer is required to create a 180 degree input to a rectifier? |
| A. | center-tapped secondary |
| B. | step-down secondary |
| C. | stepped-up secondary |
| D. | split winding primary |
| Answer» B. step-down secondary | |
| 95. |
Since diodes are destroyed by excessive current, circuits must have: |
| A. | higher voltage sources |
| B. | current limiting resistors |
| C. | more dopants |
| D. | higher current sources |
| Answer» C. more dopants | |
| 96. |
A reverse biased diode will act as an open switch. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 97. |
With a 12 V supply, a silicon diode, and a 370-ohm resistor in series, what voltage will be dropped across the diode? |
| A. | 0.3 V |
| B. | 0.7 V |
| C. | 0.9 V |
| D. | 1.4 V |
| Answer» C. 0.9 V | |
| 98. |
What is a varistor? |
| A. | a voltage-dependent resistor |
| B. | a voltage-dependent diode |
| C. | a current-dependent resistor |
| D. | a current-dependent diode |
| Answer» B. a voltage-dependent diode | |