Online Digital Electronics Test - Digital Electronics Test 8

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.
Convert the following decimal number to 8-bit binary.
35
000100102
000100112
001000112
001000102
Your Answer: Option
(Not Answered)
Correct Answer: Option

2.
A byte has 8 bits.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

3.
If the output of an enable circuit must be HIGH when the circuit is disabled, should an AND gate or an OR gate be used for the circuit?
AND gate
OR gate
Either gate can be used.
Neither gate can be used.
Your Answer: Option
(Not Answered)
Correct Answer: Option

4.
A variable is a symbol used to represent a logical quantity that can have a value of 1 or 0.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

5.

The terminal marked A on the CTR block in the given figure is the SET terminal.

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

6.
RAMs must have a input, in addition to data in.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

7.
The most widespread application of ROMs is in the storage of data and program codes that must be available on power-down in the microprocessor-based systems. These data and program codes are called firmware because they are firmly stored in hardware.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

8.
The Boolean sum of the four product terms is called the sum-of-products.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

9.
The ________ is the most popular standard logic device family today.
TTL
CMOS
ECL
None of the above
Your Answer: Option
(Not Answered)
Correct Answer: Option

10.
What is the result of taking more samples during the quantization process?
More errors in the analog-to-digital conversion
More bit requirements
More accurate signal representation
More bit requirements and more accurate signal representation
Your Answer: Option
(Not Answered)
Correct Answer: Option

11.
Polling is the process of pausing the normal sequence of instructions to cause the processor to execute a separate set of I/O instructions instead.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

12.
If [A] = 1011 1010, [B] = 0011 0110, and [C] = [A] • [B], what is [C 4..2] in decimal?
1
2
3
4
Your Answer: Option
(Not Answered)
Correct Answer: Option

13.

Refer to the display multiplexer given below. The MSD display is blank, while the LSD seems to be OK. The input and output lines to the 74157 and 7449 are checked with a scope and can be seen changing levels. The A input on the 74139 also changes; however, the 0 output on the 74139 is always LOW and the 1 output is always HIGH. The B and EN inputs on the 74139 are always LOW. What could cause the problem and what should be done to correct it?

The 74139 is defective; replace it.
The EN pin on the 74139 could have a bad connection; check the connection.
The 74139 is defective and must be replaced; or the EN pin on the 74139 could have a bad connection, which should be checked.
The MSD display is bad; replace it.
Your Answer: Option
(Not Answered)
Correct Answer: Option

14.
In order to select data input I5 of a 74151 eight-line multiplexer, the select inputs must be ________.
Your Answer: Option
(Not Answered)
Correct Answer: Option

15.
In the keypad HDL encoder, as long as all columns are high the ring counter is enabled and counting.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

16.
Which of the following characterizes an analog quantity?
Discrete levels represent changes in a quantity.
Its values follow a logarithmic curve.
It can be described with a finite number of steps.
It has a continuous set of values over a given range.
Your Answer: Option
(Not Answered)
Correct Answer: Option

17.
Sample-and-hold circuits in A/D converters are designed to:
sample and hold the output of the binary counter during the conversion process
stabilize the comparator's threshold voltage during the conversion process
stabilize the input analog signal during the conversion process
sample and hold the D/A converter staircase waveform during the conversion process
Your Answer: Option
(Not Answered)
Correct Answer: Option

18.
A binary-weighter resistor DAC is practical only up to a resolution of ________.
10 bits
2 bits
8 bits
4 bits
Your Answer: Option
(Not Answered)
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19.
PMOS and NMOS ________.
represent MOSFET devices utilizing either P-channel or N-channel devices exclusively within a given gate
are enhancement-type CMOS devices used to produce a series of high-speed logic known as 74HC
represent positive and negative MOS-type devices, which can be operated from differential power supplies and are compatible with operational amplifiers
None of the above
Your Answer: Option
(Not Answered)
Correct Answer: Option

20.
A single Schmitt trigger inverter is all that is needed to build a simple astable multivibrator.
True
False
Your Answer: Option
(Not Answered)
Correct Answer: Option

*** END OF THE TEST ***
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