Online Digital Electronics Test - Digital Electronics Test 7

Instruction:

  • This is a FREE online test. Beware of scammers who ask for money to attend this test.
  • Total number of questions: 20.
  • Time allotted: 30 minutes.
  • Each question carries 1 mark; there are no negative marks.
  • DO NOT refresh the page.
  • All the best!

Marks : 2/20


Total number of questions
20
Number of answered questions
0
Number of unanswered questions
20
Test Review : View answers and explanation for this test.

1.
What is an analog-to-digital converter?
It makes digital signals.
It takes analog signals and puts them in digital format.
It allows the use of digital signals in everyday life.
It stores information on a CD.
Your Answer: Option
(Not Answered)
Correct Answer: Option

2.
The controls on an oscilloscope that will help obtain a stable display are in the ________.
vertical section
horizontal section
trigger section
display section
Your Answer: Option
(Not Answered)
Correct Answer: Option

3.
Hex is often used in digital applications as a shorthand way to represent strings of bits.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

4.
Use Boolean algebra to find the most simplified SOP expression for F = ABD + CD + ACD + ABC + ABCD.
F = ABD + ABC + CD
F = CD + AD
F = BC + AB
F = AC + AD
Your Answer: Option
(Not Answered)
Correct Answer: Option

5.
The Boolean expression C + CD is equal to ________.
C
D
C + D
1
Your Answer: Option
(Not Answered)
Correct Answer: Option

6.
As a technician you are confronted with a TTL circuit board containing dozens of IC chips. You have taken several readings at numerous IC chips, but the readings are inconclusive because of their erratic nature. Of the possible faults listed, select the one that most probably is causing the problem.
A defective IC chip that is drawing excessive current from the power supply
A solar bridge between the inputs on the first IC chip on the board
An open input on the first IC chip on the board
A defective output IC chip that has an internal open to Vcc
Your Answer: Option
(Not Answered)
Correct Answer: Option

7.

For the XNOR gate truth table shown below, the values for w, x, y, and z are ____, ____, ____, and ____, respectively.

1, 0, 0, 1
0, 1, 0, 1
1, 1, 1, 0
1, 0, 0, 0
Your Answer: Option
(Not Answered)
Correct Answer: Option

8.
The output pulse width for a 555 monostable circuit with R1 = 3.3 k and C1 = 0.02 F is ________.
7.3 s
73 s
7.3 ms
73 ms
Your Answer: Option
(Not Answered)
Correct Answer: Option

9.
The J-K flip-flop is a standard building block of clocked (sequential) logic circuits known as a ________.
FUNCTION
logic primitive
VARIABLE
PROCESS
Your Answer: Option
(Not Answered)
Correct Answer: Option

10.
A glitch that appears on the decoded output of a ripple counter is often difficult to see on an oscilloscope because ________.
it is a random event
it occurs less frequently than the normal decoded output
it is very fast
all of the above
Your Answer: Option
(Not Answered)
Correct Answer: Option

11.
Which is not part of a hard disk drive?
Spindle
Platter
Read/write head
Valve
Your Answer: Option
(Not Answered)
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12.
Each programmable array logic (PAL) gate product is applied to an OR gate and, if combinational logic is desired, the product is ORed and then:
the polarity fuse is restored
sent to an inverter for output
sent immediately to an output pin
passed to the AND function for output
Your Answer: Option
(Not Answered)
Correct Answer: Option

13.
The programming technologies that are used in CPLD devices are all nonvolatile.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

14.
The GAL22V10 has 12 outputs pins and 10 input pins.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

15.

The symbol shown below is an AND gate.

True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

16.
Add the following BCD numbers.
0110   0111   1001
0101   1000   1000
0000  1011    0000  1111    0001  0001
0001  0001    0001  0101    0001  0001
0000  1011    0000  1111    0001  0111
0001  0001    0001  0101    0001  0111
Your Answer: Option
(Not Answered)
Correct Answer: Option

17.
Whenever a totem-pole TTL output goes from LOW to HIGH, a high-amplitude current spike is drawn from the Vcc supply. How is this effect corrected to a digital circuit?
By connecting a radio-frequency capacitor from Vcc to ground.
By using a switching power supply
By connecting a capacitor from Vout to ground
By connecting a large resistor from Vcc to Vout
Your Answer: Option
(Not Answered)
Correct Answer: Option

18.
What is the purpose of a decoder's inputs?
To allow the decoder to respond to the inputs to activate the correct output gate.
To disable the decoder outputs so that all outputs will be inactive.
To disable the inputs and activate all outputs.
To allow the decoder to respond to the inputs to activate the correct output gate, and to disable the inputs and activate all outputs.
Your Answer: Option
(Not Answered)
Correct Answer: Option

19.
In a typical IC monostable multivibrator circuit, at the falling edge of the trigger input, the output switches HIGH for a period of time determined by the ________.
value of the RC timing components
amplitude of the input trigger
frequency of the input trigger
magnitude of the dc supply voltage
Your Answer: Option
(Not Answered)
Correct Answer: Option

20.
A microcontroller is called a computer on a chip.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

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