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This section includes 96 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Electronics knowledge and support exam preparation. Choose a topic below to get started.
51. |
A very critical dimension in project management is ________. |
A. | cost |
B. | skill |
C. | time |
D. | personnel |
Answer» D. personnel | |
52. |
In the digital clock project, what is the frequency of the MOD-6 counter in the minutes section? |
A. | 1 pulse per minute |
B. | 6 pulses per minute |
C. | 10 pulses per minute |
D. | 1 pulse per hour |
Answer» E. | |
53. |
The interface of the stepper motor needs to operate in one of ________ mode(s). |
A. | one |
B. | two |
C. | three |
D. | four |
Answer» E. | |
54. |
The frequency counter measures frequency by enabling a counter to count the number of pulses of the incoming waveform during a precisely specified period of time called the sampling time. |
A. | 1 |
B. | |
Answer» C. | |
55. |
What does the ring counter in the HDL keypad application do when a key is pressed? |
A. | Count to find the row |
B. | Freeze |
C. | Count to find the column |
D. | Start the D flip-flop |
Answer» C. Count to find the column | |
56. |
In the frequency counter, when is the new count stored in the display register? |
A. | After disabling the counter |
B. | When the count buffer is full |
C. | After the sample interval is set |
D. | When the timing and control block has put it there |
Answer» B. When the count buffer is full | |
57. |
The accuracy of the frequency counter depends on the: |
A. | system clock frequency. |
B. | number of displayed digits. |
C. | sampling rate. |
D. | display update rate. |
Answer» B. number of displayed digits. | |
58. |
In the keypad application, just after the 4 ms mark the simulation imitates the release of the key by changing the column value back to F hex, which causes the d output to go into its Hi-Z state. On the next rising clock edge, what happens to dav? |
A. | It goes HIGH. |
B. | It goes LOW. |
C. | It goes to Hi-Z. |
D. | It goes to 1111H. |
Answer» C. It goes to Hi-Z. | |
59. |
When designing an HDL digital system, which is the worst mistake one can make? |
A. | Concluding that a fundamental block works perfectly |
B. | Failing to provide proper documentation |
C. | Adding blocks of code prior to testing them |
D. | Overlooking a possible VARIABLE |
Answer» B. Failing to provide proper documentation | |
60. |
One of the first steps in any HDL project is to define its scope by naming each input and output. |
A. | 1 |
B. | |
C. | 1 |
D. | |
Answer» B. | |
61. |
A frequency counter ________ a signal. |
A. | measures |
B. | displays |
C. | measures and displays |
D. | measures, displays, and generates |
Answer» D. measures, displays, and generates | |
62. |
In the keypad encoder, the ________ must hold in its current state until a key is released. |
A. | ring counter |
B. | MOD-6 counter |
C. | BCD counter |
D. | freeze bit |
Answer» B. MOD-6 counter | |
63. |
The timing and control block provides the ________ for the frequency counter. |
A. | brains |
B. | BCD counters |
C. | display register |
D. | six different frequency measurement ranges |
Answer» B. BCD counters | |
64. |
In the digital clock project, the 60 Hz signal is sent through a Schmitt-trigger circuit to produce square pulses at the rate of ________. |
A. | 1 pps |
B. | 60 pps |
C. | 100 pps |
D. | 600 pps |
Answer» C. 100 pps | |
65. |
What are two ways to remember the current state of a counter in VHDL? |
A. | With FUNCTIONS and PROCESS |
B. | With counters and timers |
C. | With SIGNAL and VARIABLE |
D. | With bit types |
Answer» D. With bit types | |
66. |
What does the major block of an HDL code emulation of a keypad include? |
A. | A sequencer |
B. | A clock |
C. | A multiplexer |
D. | A ring counter |
Answer» E. | |
67. |
Which is not a major block of an HDL frequency counter? |
A. | Display register |
B. | Decoder/display |
C. | Timing and control unit |
D. | Bit shifter |
Answer» E. | |
68. |
In the keypad application, when all columns are HIGH, the ring counter is enabled and counting, and dav is LOW, what is the status of the d outputs? |
A. | On |
B. | Off |
C. | Hi-Z |
D. | 1011 |
Answer» D. 1011 | |
69. |
Which is not a step that should be followed in project management? |
A. | Overall definition |
B. | System documentation |
C. | Synthesis and testing |
D. | System integration |
Answer» C. Synthesis and testing | |
70. |
In the digital clock project, frequency prescaling is used to take a 1 pps input and transform it into a 60 pps timing signal. |
A. | 1 |
B. | |
Answer» C. | |
71. |
In HDL, one of the strategies used in strategic planning is to find the speed requirements. |
A. | 1 |
B. | |
C. | 1 |
D. | |
Answer» C. 1 | |
72. |
One of the first steps in any HDL project is to define its scope by knowing the nature of all the signals that are interconnected to pieces of the project. |
A. | 1 |
B. | |
Answer» C. | |
73. |
In the digital clock project HDL code, the MOD-12 counter is using ________. |
A. | a BCD counter followed by a MOD-2 counter |
B. | a single HDL module |
C. | a MOD-6 counter followed by a MOD-2 counter |
D. | a MOD-12 counter followed by a D flip-flop |
Answer» C. a MOD-6 counter followed by a MOD-2 counter | |
74. |
List three basic blocks in the digital clock project. |
A. | MOD-60, MOD-12 counters |
B. | MOD-5, MOD-10, MOD-12 counters |
C. | MOD-60, MOD-10 counters |
D. | MOD-6, MOD-12, and MOD-10 counters |
Answer» E. | |
75. |
The half-step sequence of a stepper motor is created by inserting a start with only one coil energized between full steps. |
A. | 1 |
B. | |
Answer» B. | |
76. |
In the frequency counter, if the clock generator produces a 100 kHz system clock signal, how many decade counters are required to measure 1 Hz? |
A. | 6 |
B. | 5 |
C. | 4 |
D. | 3 |
Answer» C. 4 | |
77. |
In the digital clock project, a MOD-60 BCD counter is made from a MOD-10 counter cascaded to a MOD-6 BCD counter. |
A. | 1 |
B. | |
C. | 1 |
D. | |
Answer» B. | |
78. |
In the digital clock project, what type of counter is used to count to 59 seconds? |
A. | MOD-60 |
B. | MOD-6 |
C. | BCD |
D. | BCD followed by a MOD-6 |
Answer» E. | |
79. |
In a full-step sequence involving two flip-flops driving four coils of a stepper motor, how far will the stepper motor step? |
A. | 90° |
B. | 45° |
C. | 30° |
D. | 15° |
Answer» E. | |
80. |
In the keypad encoder, the ring counter is implemented using ________ that responds to the clk input. |
A. | SIGNAL |
B. | FUNCTION |
C. | CASE |
D. | PROCESS |
Answer» E. | |
81. |
In the digital clock project, the purpose of the frequency prescaler is to: |
A. | find the basic frequency. |
B. | transform a 60 pps input to a 1 pps timing signal. |
C. | prevent the clock from exceeding 12:59:59. |
D. | allow the BCD display to have a value from 00–59. |
Answer» C. prevent the clock from exceeding 12:59:59. | |
82. |
In the keypad application, what does the preset state of the ring counter define? |
A. | The proper output of the column encoder |
B. | The NANDing of the rows |
C. | The NANDing of the columns |
D. | The proper output of the row encoder |
Answer» E. | |
83. |
For the frequency counter, which is not a control signal from the control and timing block? |
A. | Clear |
B. | Enable |
C. | Reset |
D. | Store |
Answer» D. Store | |
84. |
In HDL, one of the strategies used in strategic planning is to find a way to test each piece of the project. |
A. | 1 |
B. | |
C. | 1 |
D. | |
Answer» B. | |
85. |
In the digital clock project, when does the PM indicator go high? |
A. | Never |
B. | Going from 11:59:59 to 12:00:00 |
C. | Going from 12:59:59 to 01:00:00 |
D. | On the falling edge of the clock after enable goes high |
Answer» C. Going from 12:59:59 to 01:00:00 | |
86. |
In an HDL stepper motor design, why is there more than one mode? |
A. | To change the speed of the stepper motor |
B. | To change the direction of the stepper motor |
C. | To direct drive the stepper motor |
D. | All of the above |
Answer» E. | |
87. |
Top-down design means that we start at the highest level of the hierarchy, or that the entire project is considered to exist in a closed dark box with inputs and outputs. |
A. | 1 |
B. | |
C. | 1 |
D. | |
Answer» B. | |
88. |
In the digital clock project, the 1 pps signal is used as a synchronous clock for all of the counter stages, which are ________. |
A. | advanced BCD counters |
B. | MOD-6 counters |
C. | synchronous cascaded |
D. | 1 pulse per second |
Answer» D. 1 pulse per second | |
89. |
In the keypad application, what does the data signal define? |
A. | The row and column encoded data |
B. | The ring encoded data |
C. | The freeze locator data |
D. | The ring counter data |
Answer» B. The ring encoded data | |
90. |
In the frequency counter, what is the function of the Schmitt trigger circuit? |
A. | To reduce input noise |
B. | To condition the input signal |
C. | To convert non-square waveforms |
D. | To provide a usable signal to the display unit |
Answer» D. To provide a usable signal to the display unit | |
91. |
In an HDL application of a stepper motor, after an up/down counter is built what is done next? |
A. | Build the sequencer |
B. | Test it on a simulator |
C. | Test the decoder |
D. | Design an intermediate integer variable |
Answer» C. Test the decoder | |
92. |
How is the output frequency related to the sampling interval of a frequency counter? |
A. | Directly with the sampling interval |
B. | Inversely with the sampling interval |
C. | More precision with longer sampling interval |
D. | Less precision with longer sampling interval |
Answer» D. Less precision with longer sampling interval | |
93. |
Which is not a step in strategic planning for HDL development? |
A. | There must be a way to test each piece. |
B. | Each block must fit together to make up the whole system. |
C. | The names of each input and output must be known. |
D. | The exact operation of each block must be thoroughly defined and understood. |
Answer» D. The exact operation of each block must be thoroughly defined and understood. | |
94. |
Why should a real hardware functional test be performed on the HDL stepper motor design? |
A. | To check the speed of the software |
B. | To check the current levels in the motor |
C. | To check the voltage levels of the real outputs |
D. | To provide a fully operational system |
Answer» B. To check the current levels in the motor | |
95. |
In a digital clock application, the basic frequency must be divided down to: |
A. | 1 Hz. |
B. | 60 Hz. |
C. | 100 Hz. |
D. | 1000 Hz. |
Answer» B. 60 Hz. | |
96. |
In a frequency counter, what happens at high frequencies when the sampling interval is too long? |
A. | The counter works fine. |
B. | The counter undercounts the frequency. |
C. | The measurement is less precise. |
D. | The counter overflows. |
Answer» E. | |