52 + Mcqs in Code Converters And Multiplexers Page 1 McqOptions

1.	Use the weighting factors to convert the following BCD numbers to binary. 0101 0011 0010 0110 1000
A.	01010011 001001101000
B.	11010100 100001100000
C.	110101 100001100
D.	101011 001100001
Answer» D. 101011 001100001

Discussion

2.	For the following conditions on a 7485 magnitude comparator, what will be the state of each of the three outputs? A0 = 0B0 = 1IA < B = 0 A1 = 1B1 = 0IA = B = 1 A2 = 1B2 = 0IA > B = 0 A3 = 0B3 = 0
A.	A = B = 0, A < B = 0, A > B = 1
B.	A = B = 0, A < B = 1, A > B = 0
C.	A = B = 1, A < B = 0, A > B = 0
D.	A = B = 0, A < B = 0, A > B = 0
Answer» B. A = B = 0, A < B = 1, A > B = 0

Discussion

3.	Exclusive-AND gates are needed for conversions between Gray code and binary code.
A.	1
B.
Answer» C.

Discussion

4.	The basic comparator evaluates two binary strings bit by bit and always outputs a 1.
A.	1
B.
Answer» C.

Discussion

5.	In a priority encoder, the input with the highest priority is represented on the output.
A.	1
B.
Answer» B.

Discussion

6.	The 74154 is a 1-of-16 decoder. It accepts a 4-bit binary input.
A.	1
B.
Answer» B.

Discussion

7.	Before you can make a design you must decide if you want an active-HIGH output.
A.	1
B.
Answer» B.

Discussion

8.	A basic multiplexer principle can be demonstrated through the use of a:
A.	single-pole relay
B.	DPDT switch
C.	rotary switch
D.	linear stepper
Answer» D. linear stepper

Discussion

9.	A truth table with output columns numbered 0‚Äì15 may be for which type of decoder IC?
A.	hexadecimal 1-of-16
B.	dual octal outputs
C.	binary-to-hexadecimal
D.	hexadecimal-to-binary
Answer» B. dual octal outputs

Discussion

10.	What is the status of the inputs S0, S1, and S2 of the 74151 eight-line multiplexer in order for the output Y to be a copy of input I5?
A.	S0 = 0, S1 = 1, S2 = 0
B.	S0 = 0, S1 = 0, S2 = 1
C.	S0 = 1, S1 = 1, S2 = 0
D.	S0 = 1, S1 = 0, S2 = 1
Answer» E.

Discussion

11.	How many exclusive-NOR gates would be required for an 8-bit comparator circuit?
A.	4
B.	6
C.	8
D.	10
Answer» D. 10

Discussion

12.	How is an encoder different from a decoder?
A.	The output of an encoder is a binary code for 1-of-N input.
B.	The output of a decoder is a binary code for 1-of-N input.
Answer» B. The output of a decoder is a binary code for 1-of-N input.

Discussion

13.	How many inputs are required for a 1-of-10 BCD decoder?
A.	4
B.	8
C.	10
D.	1
Answer» B. 8

Discussion

14.	A demultiplexer takes a dual input data value and routes it to one of several outputs.
A.	1
B.
Answer» C.

Discussion

15.	If two inputs are active on a priority encoder, which will be coded on the output?
A.	the higher value
B.	the lower value
C.	neither of the inputs
D.	both of the inputs
Answer» B. the lower value

Discussion

16.	A BCD is used for communication between a computer and a human being because it is too easy to deal with arithmetically.
A.	1
B.
Answer» C.

Discussion

17.	In a BCD-to-seven-segment converter, why must a code converter be utilized?
A.	to convert the 4-bit BCD into 7-bit code
B.	to convert the 4-bit BCD into 10-bit code
C.	to convert the 4-bit BCD into Gray code
D.	No conversion is necessary.
Answer» B. to convert the 4-bit BCD into 10-bit code

Discussion

18.	The expansion inputs to a comparator are used for expansion to a(n):
A.	4-bit system
B.	8-bit system
C.	BCD system
D.	counter system
Answer» C. BCD system

Discussion

19.	When two or more inputs are active simultaneously, the process is called:
A.	first-in, first-out processing
B.	priority encoding
C.	ripple blanking
D.	first-in, first-out processing or priority encoding
Answer» C. ripple blanking

Discussion

20.	Why is the Gray code more practical to use when coding the position of a rotating shaft?
A.	All digits change between counts.
B.	Two digits change between counts.
C.	Only one digit changes between counts.
Answer» D.

Discussion

21.	How many inputs will a decimal-to-BCD encoder have?
A.	4
B.	8
C.	10
D.	16
Answer» D. 16

Discussion

22.	How many select lines would be required for an 8-line-to-1-line multiplexer?
A.	2
B.	3
C.	4
D.	8
Answer» C. 4

Discussion

23.	Which of the following is not a weighted value positional numbering system:
A.	hexadecimal
B.	binary-coded decimal
C.	binary
D.	octal
Answer» C. binary

Discussion

24.	How many inputs are required for a 1-of-16 decoder?
A.	2
B.	4
C.	8
D.	16
Answer» C. 8

Discussion

25.	Most demultiplexers facilitate which type of conversion?
A.	decimal-to-hexadecimal
B.	single input, multiple outputs
C.	ac to dc
D.	odd parity to even parity
Answer» C. ac to dc

Discussion

26.	The primary use for Gray code is:
A.	coded representation of a shaft's mechanical position
B.	turning on/off software switches
C.	to represent the correct ASCII code to indicate the angular position of a shaft on rotating machinery
D.	to convert the angular position of a shaft on rotating machinery into hexadecimal code
Answer» B. turning on/off software switches

Discussion

27.	A circuit that responds to a specific set of signals to produce a related digital signal output is called a(n):
A.	BCD matrix
B.	display driver
C.	encoder
D.	decoder
Answer» D. decoder

Discussion

28.	For the following conditions on a 7485 magnitude comparator, what will be the state of each of the three outputs? A0 = 0B0 = 1IA < B = 0 A1 = 1B1 = 0IA = B = 1 A2 = 1B2 = 0IA > B = 0 A3 = 0B3 = 0¬†
A.	A = B = 0, A < B = 0, A > B = 1
B.	A = B = 0, A < B = 1, A > B = 0
C.	A = B = 1, A < B = 0, A > B = 0
D.	A = B = 0, A < B = 0, A > B = 0
Answer» B. A = B = 0, A < B = 1, A > B = 0

Discussion

29.	The digit bus and display bus are each just a common set of conductors shared by the digit storage registers and display segments.
A.	1
B.
C.	1
D.
Answer» B.

Discussion

30.	Why can a CMOS IC be used as both a multiplexer and a demultiplexer?
A.	It cannot be used as both.
B.	CMOS uses bidirectional switches.
Answer» C.

Discussion

31.	How many 74184 BCD-to-binary converters would be required to convert two complete BCD digits to a binary number?
A.	8
B.	4
C.	2
D.	1
Answer» D. 1

Discussion

32.	One multiplexer can take the place of:
A.	several SSI logic gates
B.	combinational logic circuits
C.	several Ex-NOR gates
D.	several SSI logic gates or combinational logic circuits
Answer» E.

Discussion

33.	One way to convert BCD to binary using the hardware approach is:
A.	with MSI IC circuits
B.	with a keyboard encoder
C.	with an ALU
D.	UART
Answer» B. with a keyboard encoder

Discussion

34.	What control signals may be necessary to operate a 1-line-to-16 line decoder?
A.	flasher circuit control signal
B.	a LOW on all gate enable inputs
C.	input from a hexadecimal counter
D.	a HIGH on all gate enable circuits
Answer» C. input from a hexadecimal counter

Discussion

35.	The inputs/outputs of an analog multiplexer/demultiplexer are:
A.	bidirectional
B.	unidirectional
C.	even parity
D.	binary-coded decimal
Answer» B. unidirectional

Discussion

36.	How many possible outputs would a decoder have with a 6-bit binary input?
A.	16
B.	32
C.	64
D.	128
Answer» D. 128

Discussion

37.	What do the mathematical symbols A < b and A > B mean?
A.	A < B means A is greater than B. A > B means A is less than B.
B.	A > B means A is less than B. A < B means A is greater than B.
C.	A < B means A is less than B. A > B means A is greater than B.
Answer» D.

Discussion

38.	The microcontroller needs to use only three input lines to monitor eight separate points.
A.	1
B.
Answer» B.

Discussion

39.	Why is a demultiplexer called a data distributor?
A.	The input will be distributed to one of the outputs.
B.	One of the inputs will be selected for the output.
C.	The output will be distributed to one of the inputs.
Answer» B. One of the inputs will be selected for the output.

Discussion

40.	From the following list of input conditions, determine the state of the five output leads on a 74148 octal-to-binary encoder. I0 = 1 I3 = 1 I6 = 1 I1 = 1 I4 = 0 I7 = 1 I2 = 1 I5 = 1 EI = 0
A.	GS = L, A0 = L, A1 = L, A2 = H, EO = H
B.	GS = L, A0 = H, A1 = L, A2 = L, EO = H
C.	GS = L, A0 = L, A1 = H, A2 = L, EO = H
D.	GS = L, A0 = H, A1 = H, A2 = L, EO = H
Answer» E.

Discussion

41.	What is the function of an enable input on a multiplexer chip?
A.	to apply Vcc
B.	to connect ground
C.	to active the entire chip
D.	to active one half of the chip
Answer» D. to active one half of the chip

Discussion

42.	In a Gray code, each number is 3 greater than the binary representation of that number.
A.	1
B.
Answer» C.

Discussion

43.	A microcontroller differs from a microprocessor in that it has several ________ ports and ________ built into its architecture, making it better suited for ________ applications.
A.	communication, PROMs, control
B.	parallel, logic gates, processing
C.	input/output, memory, control
D.	data, memory, decoding
Answer» D. data, memory, decoding

Discussion

44.	One application of a digital multiplexer is to facilitate:
A.	data generation
B.	serial-to-parallel conversion
C.	parity checking
D.	data selector
Answer» E.

Discussion

45.	Use the weighting factors to convert the following BCD numbers to binary. 0101¬†0011¬†¬†¬†¬†¬†¬†¬†¬†0010¬†0110¬†1000
A.	01010011¬†¬†¬†¬†001001101000
B.	11010100¬†¬†¬†¬†100001100000
C.	110101¬†¬†¬†¬†¬†¬†¬†¬†100001100
D.	101011¬†¬†¬†¬†¬†¬†¬†¬†001100001
Answer» D. 101011¬†¬†¬†¬†¬†¬†¬†¬†001100001

Discussion

46.	Which digital system translates coded characters into a more useful form?
A.	encoder
B.	display
C.	counter
D.	decoder
Answer» E.

Discussion

47.	A BCD decoder will have how many rows in its truth table?
A.	10
B.	9
C.	8
D.	3
Answer» B. 9

Discussion

48.	How can the active condition (HIGH or LOW) or the decoder output be determined from the logic symbol?
A.	A bubble indicates active-HIGH.
B.	A bubble indicates active-LOW.
C.	A square indicates active-HIGH.
D.	A square indicates active-LOW.
Answer» C. A square indicates active-HIGH.

Discussion

49.	A principle regarding most IC decoders is that when the correct input is present, the related output will switch:
A.	active-HIGH
B.	to a high impedance
C.	to an open
D.	active-LOW
Answer» E.

Discussion

50.	In a multiplexer, the data select control inputs are responsible for determining which data input is selected to be transmitted to the data output line.
A.	1
B.
C.	1
D.
Answer» B.

Discussion

Explore topic-wise MCQs in Digital Electronics.

Use the weighting factors to convert the following BCD numbers to binary. 0101 0011 0010 0110 1000

For the following conditions on a 7485 magnitude comparator, what will be the state of each of the three outputs? A0 = 0B0 = 1IA < B = 0 A1 = 1B1 = 0IA = B = 1 A2 = 1B2 = 0IA > B = 0 A3 = 0B3 = 0

Exclusive-AND gates are needed for conversions between Gray code and binary code.

The basic comparator evaluates two binary strings bit by bit and always outputs a 1.

In a priority encoder, the input with the highest priority is represented on the output.

The 74154 is a 1-of-16 decoder. It accepts a 4-bit binary input.

Before you can make a design you must decide if you want an active-HIGH output.

A basic multiplexer principle can be demonstrated through the use of a:

A truth table with output columns numbered 0‚Äì15 may be for which type of decoder IC?

What is the status of the inputs S0, S1, and S2 of the 74151 eight-line multiplexer in order for the output Y to be a copy of input I5?

How many exclusive-NOR gates would be required for an 8-bit comparator circuit?

How is an encoder different from a decoder?

How many inputs are required for a 1-of-10 BCD decoder?

A demultiplexer takes a dual input data value and routes it to one of several outputs.

If two inputs are active on a priority encoder, which will be coded on the output?

A BCD is used for communication between a computer and a human being because it is too easy to deal with arithmetically.

In a BCD-to-seven-segment converter, why must a code converter be utilized?

The expansion inputs to a comparator are used for expansion to a(n):

When two or more inputs are active simultaneously, the process is called:

Why is the Gray code more practical to use when coding the position of a rotating shaft?

How many inputs will a decimal-to-BCD encoder have?

How many select lines would be required for an 8-line-to-1-line multiplexer?

Which of the following is not a weighted value positional numbering system:

How many inputs are required for a 1-of-16 decoder?

Most demultiplexers facilitate which type of conversion?

The primary use for Gray code is:

A circuit that responds to a specific set of signals to produce a related digital signal output is called a(n):

For the following conditions on a 7485 magnitude comparator, what will be the state of each of the three outputs? A0 = 0B0 = 1IA < B = 0 A1 = 1B1 = 0IA = B = 1 A2 = 1B2 = 0IA > B = 0 A3 = 0B3 = 0¬†

The digit bus and display bus are each just a common set of conductors shared by the digit storage registers and display segments.

Why can a CMOS IC be used as both a multiplexer and a demultiplexer?

How many 74184 BCD-to-binary converters would be required to convert two complete BCD digits to a binary number?

One multiplexer can take the place of:

One way to convert BCD to binary using the hardware approach is:

What control signals may be necessary to operate a 1-line-to-16 line decoder?

The inputs/outputs of an analog multiplexer/demultiplexer are:

How many possible outputs would a decoder have with a 6-bit binary input?

What do the mathematical symbols A < b and A > B mean?

The microcontroller needs to use only three input lines to monitor eight separate points.

Why is a demultiplexer called a data distributor?

From the following list of input conditions, determine the state of the five output leads on a 74148 octal-to-binary encoder. I0 = 1 I3 = 1 I6 = 1 I1 = 1 I4 = 0 I7 = 1 I2 = 1 I5 = 1 EI = 0

What is the function of an enable input on a multiplexer chip?

In a Gray code, each number is 3 greater than the binary representation of that number.

A microcontroller differs from a microprocessor in that it has several ________ ports and ________ built into its architecture, making it better suited for ________ applications.

One application of a digital multiplexer is to facilitate:

Use the weighting factors to convert the following BCD numbers to binary. 0101¬†0011¬†¬†¬†¬†¬†¬†¬†¬†0010¬†0110¬†1000

Which digital system translates coded characters into a more useful form?

A BCD decoder will have how many rows in its truth table?

How can the active condition (HIGH or LOW) or the decoder output be determined from the logic symbol?

A principle regarding most IC decoders is that when the correct input is present, the related output will switch:

In a multiplexer, the data select control inputs are responsible for determining which data input is selected to be transmitted to the data output line.

A microcontroller differs from a microprocessor in that it has several ports and built into its architecture, making it better suited for applications.