2291 + Mcqs in Digital Electronics Page 20 McqOptions

951.	The 8051 has ________ 16-bit counter/timers.
A.	1
B.	2
C.	3
D.	4
Answer» C. 3

Discussion

952.	The address space of the 8051 is divided into four distinct areas: internal data, external data, internal code, and external code.
A.	True
B.	False
Answer» B. False

Discussion

953.	Data transfer from I/O to external data memory can only be done with the MOVX command.
A.	True
B.	False
Answer» B. False

Discussion

954.	The difference between a PLA and a PAL is:
A.	The PLA has a programmable OR plane and a programmable AND plane, while the PAL only has a programmable AND plane.
B.	The PAL has a programmable OR plane and a programmable AND plane, while the PLA only has a programmable AND plane.
C.	The PAL has more possible product terms than the PLA.
D.	PALs and PLAs are the same thing.
Answer» B. The PAL has a programmable OR plane and a programmable AND plane, while the PLA only has a programmable AND plane.

Discussion

955.	ALM is the acronym for ________.
A.	Array Logic Matrix
B.	Arithmetic Logic Module
C.	Asynchronous Local Modulator
D.	Adaptive Logic Module
Answer» E.

Discussion

956.	The GAL16V8 has:
A.	16 dedicated inputs.
B.	8 special function pins.
C.	8 pins that are used as inputs or outputs.
D.	All of the above
Answer» D. All of the above

Discussion

957.	PALs tend to execute ________ logic.
A.	SAP
B.	SOP
C.	PLA
D.	SPD
Answer» C. PLA

Discussion

958.	If a typical PC uses a 20-bit address code, how much memory can the CPU address?
A.	20 MB
B.	10 MB
C.	1 MB
D.	580 MB
Answer» D. 580 MB

Discussion

959.	Fan-out is specified in terms of ________.
A.	voltage
B.	current
C.	wattage
D.	unit loads
Answer» E.

Discussion

960.	Which of the following is true for a 5-variable Karnaugh map?
A.	There is no such thing.
B.	It can be used only with the aid of a computer.
C.	It is made up of two 4-variable Karnaugh maps.
D.	It is made up of a 2-variable and a 3-variable Karnaugh map.
Answer» D. It is made up of a 2-variable and a 3-variable Karnaugh map.

Discussion

961.	One reason for using the sum-of-products form is that it can be implemented using all ________ gates without much difficulty.
A.	NOR
B.	NAND
C.	AND
D.	DOOR
Answer» C. AND

Discussion

962.	The duty cycle of the most significant bit from a 4-bit (0 9) BCD counter is ________.
A.	10%
B.	20%
C.	50%
D.	80%
Answer» C. 50%

Discussion

963.	To which pin on the RAM chip does the address decoder connect in order to signal which memory chip is being accessed?
A.	The address input
B.	The output enable
C.	The chip enable
D.	The data input
Answer» D. The data input

Discussion

964.	What is another name for digital circuitry called sequential logic?
A.	logic macrocell
B.	logic array
C.	flip-flop memory circuitry
D.	inverter
Answer» D. inverter

Discussion

965.	A GAL is a programmable/reprogrammable PAL.
A.	True
B.	False
Answer» B. False

Discussion

966.	An offset error in a DAC will show up as an incorrect analog output ________.
A.	only for higher value inputs
B.	only for lower value inputs
C.	only for certain (scattered) inputs
D.	for all inputs
Answer» E.

Discussion

967.	In a binary system there are only two symbols.
A.	True
B.	False
Answer» B. False

Discussion

968.	The duty cycle of a square wave is ________.
A.	10%
B.	25%
C.	50%
D.	100%
Answer» D. 100%

Discussion

969.	Convert hexadecimal value C1 to binary.
A.	11000001
B.	1000111
C.	111000100
D.	111000001
Answer» B. 1000111

Discussion

970.	A logic probe is used to test the pins of a 7411 IC with the following results. Is there a problem with the chip and if so, what is the problem?
A.	Pin 6 should be ON.
B.	Pin 6 should be pulsing.
C.	Pin 8 should be ON.
D.	no problem
Answer» C. Pin 8 should be ON.

Discussion

971.	How many inputs of a four-input AND gate must be HIGH in order for the output of the logic gate to go HIGH?
A.	any one of the inputs
B.	any two of the inputs
C.	any three of the inputs
D.	all four inputs
Answer» E.

Discussion

972.	With regard to a D latch, ________.
A.	the Q output follows the D input when EN is LOW
B.	the Q output is opposite the D input when EN is LOW
C.	the Q output follows the D input when EN is HIGH
D.	the Q output is HIGH regardless of EN's input state
Answer» D. the Q output is HIGH regardless of EN's input state

Discussion

973.	A bidirectional 4-bit shift register is storing the nibble 1101. Its input is HIGH. The nibble 1011 is waiting to be entered on the serial data-input line. After three clock pulses, the shift register is storing ________.
A.	1101
B.	0111
C.	0001
D.	1110
Answer» C. 0001

Discussion

974.	What is the difference between a ring shift counter and a Johnson shift counter?
A.	There is no difference.
B.	A ring is faster.
C.	The feedback is reversed.
D.	The Johnson is faster.
Answer» D. The Johnson is faster.

Discussion

975.	A 64-Mbyte SIMM is installed into a system, but when a memory test is executed, the SIMM is detected as a 32-Mbyte device. What is a possible cause?
A.	The memory module was not installed properly.
B.	The voltage on the memory module is incorrect.
C.	The most significant address line is stuck high or low.
D.	The address decoder on the SIMM is faulty.
Answer» E.

Discussion

976.	Which of the following is one of the basic characteristics of DRAMs?
A.	DRAMs must have a constantly changing input.
B.	DRAMs must be periodically refreshed in order to be able to retain data.
C.	DRAMs have a broader "dynamic" storage range than other types of memories.
D.	DRAMs are simpler devices than other types of memories.
Answer» C. DRAMs have a broader "dynamic" storage range than other types of memories.

Discussion

977.	The PAL structure is able to perform any sum-of-products (SOP) operation.
A.	True
B.	False
Answer» B. False

Discussion

978.	What programmable technology is used in FPGA devices?
A.	SRAM
B.	FLASH
C.	Antifuse
D.	All of the above
Answer» E.

Discussion

979.	Of the methods listed, the fastest A/D conversion is done by a ________.
A.	single-slope ramp converter
B.	dual-slope ramp converter
C.	successive-approximation converter
D.	tracking converter
Answer» D. tracking converter

Discussion

980.	TTL is alive and well, particularly in ________.
A.	industrial applications
B.	educational applications
C.	military applications
D.	commercial applications
Answer» C. military applications

Discussion

981.	Which timing diagram shown below is correct for an inverter?
A.	a
B.	b
C.	c
D.	d
Answer» C. c

Discussion

982.	Determine the voltage on the collector Vc of the given transistor circuit.
A.	0 V
B.	+10 V
C.	+4.7 V
D.	+0.5 V
Answer» C. +4.7 V

Discussion

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

Discussion

984.	The purpose of a pull-up resistor is to keep a terminal at a ________ level when it would normally be at a ________ level.
A.	LOW, float
B.	HIGH, float
C.	clock, float
D.	pulsed, float
Answer» C. clock, float

Discussion

985.	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

Discussion

986.	The interface of the stepper motor needs to operate in one of ________ mode(s).
A.	one
B.	two
C.	three
D.	four
Answer» E.

Discussion

987.	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

Discussion

988.	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

Discussion

989.	In the digital clock project, a 60 pps input is transformed into a 1 pps timing signal. The block is called ________.
A.	a BCD counter
B.	a MOD-60 counter
C.	frequency divider
D.	frequency prescaling
Answer» E.

Discussion

990.	In the keypad encoder, the ________ detects when a key is pressed.
A.	ring counter
B.	MOD-6 counter
C.	BCD counter
D.	freeze bit
Answer» E.

Discussion

991.	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

Discussion

992.	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

Discussion

993.	The term race condition describes the time that an active signal must be present at the input to a flip-flop before an active clock edge is applied.
A.	True
B.	False
Answer» C.

Discussion

994.	Each ________, starting at the simplest level, should be built in HDL.
A.	subsystem
B.	block
C.	circuit
D.	function
Answer» B. block

Discussion

995.	In the keypad encoder, the ________ activate(s) the freeze bit only when one column is low.
A.	NAND columns
B.	CASE structure
C.	freeze function
D.	BCD counter
Answer» C. freeze function

Discussion

996.	The output of a phototransister is determined by the presence or absence of light at its base input.
A.	True
B.	False
Answer» B. False

Discussion

997.	A Schmitt trigger has a positive feedback circuit and experiences a phenomenon called hysteresis.
A.	True
B.	False
Answer» C.

Discussion

998.	A monostable multivibrator is commonly called a two shot.
A.	True
B.	False
Answer» C.

Discussion

999.	A series RC circuit can be used to generate a power-up (automatic) reset signal.
A.	True
B.	False
Answer» B. False

Discussion

1000.	The 7805 will get very hot if your circuit draws more than 0.5 A.
A.	True
B.	False
Answer» B. False

Discussion

Explore topic-wise MCQs in Engineering.

The 8051 has ________ 16-bit counter/timers.

The address space of the 8051 is divided into four distinct areas: internal data, external data, internal code, and external code.

Data transfer from I/O to external data memory can only be done with the MOVX command.

The difference between a PLA and a PAL is:

ALM is the acronym for ________.

The GAL16V8 has:

PALs tend to execute ________ logic.

If a typical PC uses a 20-bit address code, how much memory can the CPU address?

Fan-out is specified in terms of ________.

Which of the following is true for a 5-variable Karnaugh map?

One reason for using the sum-of-products form is that it can be implemented using all ________ gates without much difficulty.

The duty cycle of the most significant bit from a 4-bit (0 9) BCD counter is ________.

To which pin on the RAM chip does the address decoder connect in order to signal which memory chip is being accessed?

What is another name for digital circuitry called sequential logic?

A GAL is a programmable/reprogrammable PAL.

An offset error in a DAC will show up as an incorrect analog output ________.

In a binary system there are only two symbols.

The duty cycle of a square wave is ________.

Convert hexadecimal value C1 to binary.

A logic probe is used to test the pins of a 7411 IC with the following results. Is there a problem with the chip and if so, what is the problem?

How many inputs of a four-input AND gate must be HIGH in order for the output of the logic gate to go HIGH?

With regard to a D latch, ________.

A bidirectional 4-bit shift register is storing the nibble 1101. Its input is HIGH. The nibble 1011 is waiting to be entered on the serial data-input line. After three clock pulses, the shift register is storing ________.

What is the difference between a ring shift counter and a Johnson shift counter?

A 64-Mbyte SIMM is installed into a system, but when a memory test is executed, the SIMM is detected as a 32-Mbyte device. What is a possible cause?

Which of the following is one of the basic characteristics of DRAMs?

The PAL structure is able to perform any sum-of-products (SOP) operation.

What programmable technology is used in FPGA devices?

Of the methods listed, the fastest A/D conversion is done by a ________.

TTL is alive and well, particularly in ________.

Which timing diagram shown below is correct for an inverter?

Determine the voltage on the collector Vc of the given transistor circuit.

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

The purpose of a pull-up resistor is to keep a terminal at a ________ level when it would normally be at a ________ level.

In the keypad encoder, the ________ must hold in its current state until a key is released.

The interface of the stepper motor needs to operate in one of ________ mode(s).

In the digital clock project, the 60 Hz signal is sent through a Schmitt-trigger circuit to produce square pulses at the rate of ________.

In the digital clock project, the 1 pps signal is used as a synchronous clock for all of the counter stages, which are ________.

In the digital clock project, a 60 pps input is transformed into a 1 pps timing signal. The block is called ________.

In the keypad encoder, the ________ detects when a key is pressed.

The timing and control block provides the ________ for the frequency counter.

In the digital clock project HDL code, the MOD-12 counter is using ________.

The term race condition describes the time that an active signal must be present at the input to a flip-flop before an active clock edge is applied.

Each ________, starting at the simplest level, should be built in HDL.

In the keypad encoder, the ________ activate(s) the freeze bit only when one column is low.

The output of a phototransister is determined by the presence or absence of light at its base input.

A Schmitt trigger has a positive feedback circuit and experiences a phenomenon called hysteresis.

A monostable multivibrator is commonly called a two shot.

A series RC circuit can be used to generate a power-up (automatic) reset signal.

The 7805 will get very hot if your circuit draws more than 0.5 A.

The purpose of a pull-up resistor is to keep a terminal at a level when it would normally be at a level.