# Online Digital Electronics Test - Digital Electronics Test 7

Instruction:

• This is a FREE online test. DO NOT pay money to anyone to attend this test.
• Total number of questions : 20.
• Time alloted : 30 minutes.
• Each question carry 1 mark, no negative marks.
• DO NOT refresh the page.
• All the best :-).

1.

What is an analog-to-digital converter?

A.
 It makes digital signals.
B.
 It takes analog signals and puts them in digital format.
C.
 It allows the use of digital signals in everyday life.
D.
 It stores information on a CD.

Correct Answer: Option B

Learn more problems on : Digital Concepts

2.

The controls on an oscilloscope that will help obtain a stable display are in the ________.

A.
 vertical section
B.
 horizontal section
C.
 trigger section
D.
 display section

Correct Answer: Option C

Learn more problems on : Digital Concepts

3.

Hex is often used in digital applications as a shorthand way to represent strings of bits.

A.
 True
B.
 False

Correct Answer: Option A

Learn more problems on : Number Systems and Codes

4.

Use Boolean algebra to find the most simplified SOP expression for F = ABD + CD + ACD + ABC + ABCD.

A.
 F = ABD + ABC + CD
B.
 F = CD + AD
C.
 F = BC + AB
D.
 F = AC + AD

Correct Answer: Option A

Learn more problems on : Boolean Algebra and Logic Simplification

5.

The Boolean expression C + CD is equal to ________.

A.
 C
B.
 D
C.
 C + D
D.
 1

Correct Answer: Option A

Learn more problems on : Boolean Algebra and Logic Simplification

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.
 A defective IC chip that is drawing excessive current from the power supply
B.
 A solar bridge between the inputs on the first IC chip on the board
C.
 An open input on the first IC chip on the board
D.
 A defective output IC chip that has an internal open to Vcc

Correct Answer: Option C

Learn more problems on : Combinational Logic Circuits

7.

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

A.
 1, 0, 0, 1
B.
 0, 1, 0, 1
C.
 1, 1, 1, 0
D.
 1, 0, 0, 0

Correct Answer: Option A

Learn more problems on : Combinational Logic Circuits

8.

The output pulse width for a 555 monostable circuit with R1 = 3.3 k and C1 = 0.02 F is ________.

A.
 7.3 s
B.
 73 s
C.
 7.3 ms
D.
 73 ms

Correct Answer: Option B

9.

The J-K flip-flop is a standard building block of clocked (sequential) logic circuits known as a ________.

A.
 FUNCTION
B.
 logic primitive
C.
 VARIABLE
D.
 PROCESS

Correct Answer: Option B

10.

A glitch that appears on the decoded output of a ripple counter is often difficult to see on an oscilloscope because ________.

A.
 it is a random event
B.
 it occurs less frequently than the normal decoded output
C.
 it is very fast
D.
 all of the above

Correct Answer: Option D

11.

Which is not part of a hard disk drive?

A.
 Spindle
B.
 Platter
C.
D.
 Valve

Correct Answer: Option D

Learn more problems on : Memory and Storage

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:

A.
 the polarity fuse is restored
B.
 sent to an inverter for output
C.
 sent immediately to an output pin
D.
 passed to the AND function for output

Correct Answer: Option B

Learn more problems on : Programmable Logic Device

13.

The programming technologies that are used in CPLD devices are all nonvolatile.

A.
 True
B.
 False

Correct Answer: Option A

Learn more problems on : Programmable Logic Device

14.

The GAL22V10 has 12 outputs pins and 10 input pins.

A.
 True
B.
 False

Correct Answer: Option B

Learn more problems on : Programmable Logic Device

15.

The symbol shown below is an AND gate.

A.
 True
B.
 False

Correct Answer: Option A

Learn more problems on : Describing Logic Circuits

16.

Add the following BCD numbers.
 0110 0111 1001 0101 1000 1000

A.
 0000  1011    0000  1111    0001  0001
B.
 0001  0001    0001  0101    0001  0001
C.
 0000  1011    0000  1111    0001  0111
D.
 0001  0001    0001  0101    0001  0111

Correct Answer: Option D

Learn more problems on : Digital Arithmetic Operations and Circuits

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?

A.
 By connecting a radio-frequency capacitor from Vcc to ground.
B.
 By using a switching power supply
C.
 By connecting a capacitor from Vout to ground
D.
 By connecting a large resistor from Vcc to Vout

Correct Answer: Option A

Learn more problems on : Integrated-Circuit Logic Families

18.

What is the purpose of a decoder's inputs?

A.
 To allow the decoder to respond to the inputs to activate the correct output gate.
B.
 To disable the decoder outputs so that all outputs will be inactive.
C.
 To disable the inputs and activate all outputs.
D.
 To allow the decoder to respond to the inputs to activate the correct output gate, and to disable the inputs and activate all outputs.

Correct Answer: Option D

Learn more problems on : MSI Logic Circuits

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 ________.

A.
 value of the RC timing components
B.
 amplitude of the input trigger
C.
 frequency of the input trigger
D.
 magnitude of the dc supply voltage

Correct Answer: Option A

Learn more problems on : Multivibrators and 555 Timer

20.

A microcontroller is called a computer on a chip.

A.
 True
B.
 False

Correct Answer: Option A

Learn more problems on : The 8051 Microcontroller