1271 + Mcqs in Digital Electronics Page 17 McqOptions

801.	How many and what are the machine cycles needed for execution of MOV D, C?
A.	1, Fetch
B.	2, Fetch and Memory Read
C.	2, Memory Read and Memory write
D.	2, Fetch 4 Bus idle
Answer» B. 2, Fetch and Memory Read

Discussion

802.	Vectored interrupt is an interrupt that takes the program to a vector location. TRAP vectors to 0024 FI, RST 7.5 to 003 CH, RST 6.5 to 0034 H and
A.	RST 5.5
B.	RST 6.5
C.	24 H to 48 H
D.	RST 5.5 to 002 CH
Answer» E.

Discussion

803.	The value of program counter of 6800 at power on are after reset is
A.	0
B.	FFFE
C.	User Programmable
D.	FFFF
Answer» C. User Programmable

Discussion

804.	In 8085 microprocessor, what is the length of SP (stack) pointer?
A.	6 bits
B.	8 bits
C.	12 bits
D.	16 bits
Answer» E.

Discussion

805.	In the given figure shows a 3 bit shift register using TTL flip flops. Initially all the flip flops are set to 0 state. After 8 clock pulses
A.	A = 1, B = 1, C = 1
B.	A = 1, B = 1, C = 0
C.	A = 0, B = 1, C = 1
D.	A = 0, B = 0, C = 1
Answer» B. A = 1, B = 1, C = 0

Discussion

806.	A 6 MHz channel is used by a digital signalling system initializing four-level signals. The maximum possible transmission rate is
A.	6M bands/s
B.	12M bands/s
C.	6 M bits/s
D.	12M bits/s
Answer» B. 12M bands/s

Discussion

807.	By placing an inverter between both inputs of an S-R flip-flop, the resulting flip-flop becomes
A.	J-K flip-flop
B.	D-flip-flop
C.	T-flip-flop
D.	Master salve JK flip-flop
Answer» C. T-flip-flop

Discussion

808.	What will be the maximum conversion time in 6 bit dual slope A/D converter uses a reference of -6v and a 1 MHz clock. It uses a fixed count of 40 (101000).
A.	108 sec
B.	63 Œº sec
C.	40 sec
D.	80 Œº sec
Answer» B. 63 Œº sec

Discussion

809.	When two 4 bit parallel adders are cascaded we get
A.	4 bit parallel adder
B.	8 bit parallel adder
C.	16 bit parallel adder
D.	none of the above
Answer» C. 16 bit parallel adder

Discussion

810.	Assuming accumulator contain A 64 and the carry is set (1). What will accumulator (A) and carry (CY) contain after ANA A?
A.	A 6 H, 1
B.	A 6 H, 0
C.	00 H, 0
D.	00 H, 1
Answer» C. 00 H, 0

Discussion

811.	The series 54 H/74 H denotes
A.	Standard TTL
B.	High speed TTL
C.	Low Power TTL
D.	High Power TTL
Answer» C. Low Power TTL

Discussion

812.	The output of the circuit shown below will be of the frequency
A.	125 Hz
B.	250 Hz
C.	500 Hz
D.	750 Hz
Answer» C. 500 Hz

Discussion

813.	In a mod-12 counter the input clock frequency is 10 kHz. The output frequency is
A.	0.833 kHz
B.	1.0 kHz
C.	0.91 kHz
D.	0.77 kHz
Answer» B. 1.0 kHz

Discussion

814.	For edge triggering in flip flops, manufacturers use
A.	RC circuit
B.	direct coupled design
C.	either RC circuit or direct coupled design
D.	none of the above
Answer» C. either RC circuit or direct coupled design

Discussion

815.	A universal register
A.	accepts serial input
B.	accepts Parallel input
C.	gives serial and Parallel output
D.	all of the above
Answer» E.

Discussion

816.	The MOS symbol shown indicates that It is depletion typeIt is enhancement typeIt is channelIt is P-channelElectrons flow from s to DHoles flow from D to s The true statements are
A.	1, 3, 6
B.	1, 3, 5
C.	2, 4, 6
D.	2, 3, 5
Answer» E.

Discussion

817.	The contents of the program counter after the call operation point to the first instruction on the
A.	stack
B.	subroutine
C.	either of the above
D.	none of the above
Answer» C. either of the above

Discussion

818.	Which of the following statements defines a full adder?
A.	It adds two binary digits and produces their SUM and CARRY
B.	It adds three inputs (two binary digits and a carry) and produces their SUM and CARRY
C.	It has two inputs and two outputs
D.	None of the above
Answer» C. It has two inputs and two outputs

Discussion

819.	The noise margin of a TTL gate is about
A.	0.2 V
B.	0.4 V
C.	0.6 V
D.	0.8 V
Answer» D. 0.8 V

Discussion

820.	The radix of a hexadecimal system is
A.	2
B.	3
C.	8
D.	16
Answer» E.

Discussion

821.	The logic represented by the abbreviation ECL is
A.	Emitter Coupled Logic
B.	Electron Carrier Logic
C.	Encoding Clock Logic
D.	Electrostatic Channel Logic
Answer» B. Electron Carrier Logic

Discussion

822.	As compared to TTL, ECL has
A.	lower power dissipation
B.	lower propagation delay
C.	higher propagation delay
D.	higher noise margin
Answer» C. higher propagation delay

Discussion

823.	In 8085 microprocessor, the RST 5.5 interrupt service routine start from location
A.	0020 H
B.	0024 H
C.	0028 H
D.	002 CH
Answer» E.

Discussion

824.	The minimum number of 2 input NAND gates required to implement Boolean function A B C is A, B, C are available is
A.	2
B.	3
C.	5
D.	6
Answer» D. 6

Discussion

825.	The minimum number of NAND gates required to implement the Boolean function A +AB + ABC is equal to
A.	0
B.	1
C.	4
D.	7
Answer» B. 1

Discussion

826.	What is the decimal equivalent of the binary number shown in fourth row?
A.	79
B.	97
C.	117
D.	127
Answer» C. 117

Discussion

827.	A microprocessor with a 16 bit address bus is used in a linear memory selection configuration. Address bus lines are directly uses as chip selects of memory chips with 4 memory chips the maximum addressable memory space is
A.	64 k
B.	16 k
C.	8 k
D.	4 k
Answer» B. 16 k

Discussion

828.	What kind of signal does the times produce?
A.	Single pulse
B.	Square wave
C.	Continuous pulse
D.	No signal
Answer» B. Square wave

Discussion

829.	Which of the following pairs of octal and binary numbers are not equal?
A.	111 110112 = 7678
B.	1101101012 = 6658
C.	110102 = 38
D.	10101.112 = 25.68
Answer» D. 10101.112 = 25.68

Discussion

830.	A 10 bit D/A converter gives a maximum output of 10.23 V. The resolution is
A.	10 mV
B.	20 mV
C.	15 mV
D.	25 mV
Answer» B. 20 mV

Discussion

831.	A sequence detector is required to give a logical output of 1 whenever the sequence 1011 is detected in the incoming pulse stream. Minimum number of flip-flops needed to built the sequence detector is
A.	4
B.	3
C.	1
D.	2
Answer» C. 1

Discussion

832.	In a digital system, the maximum clock frequency that can be used with Master/Slave Clocked flip-flops having total propagation delay of 200 Œºsec is
A.	20 MHz
B.	50 MHz
C.	100 MHz
D.	200 MHz
Answer» C. 100 MHz

Discussion

833.	Out of SAM and RAM
A.	access time in both does not depend on address location
B.	in SAM access time depends on address location but not in RAM
C.	in RAM access time depends on address location but not in SAM
D.	in both the access time depends on storage location
Answer» C. in RAM access time depends on address location but not in SAM

Discussion

834.	What is the normal range of analog input voltage?
A.	0 to 1 V
B.	0 to 5 V
C.	5 to 15 V
D.	15V to 30V
Answer» C. 5 to 15 V

Discussion

835.	In 2's complement form, - 2 is
A.	1011
B.	1110
C.	1100
D.	1010
Answer» C. 1100

Discussion

836.	A ripple counter has 4 bits and uses flip flops with propagation delay time of 25 ns. The maximum possible time for change of state will be
A.	25 ns
B.	50 ns
C.	75 ns
D.	100 ns
Answer» E.

Discussion

837.	EEPROM is also known as
A.	UVPROM
B.	EAPROM
C.	both UVPROM and EAPROM
D.	none of the above
Answer» C. both UVPROM and EAPROM

Discussion

838.	Which binary addition is incorrect?
A.	1001.1 + 1011.01 = 10100.11
B.	100010 + 1000101 = 1001010
C.	0.0011 + 0.1110 = 1.1
D.	1011.01 + 1001.11 = 10111
Answer» E.

Discussion

839.	A 6 bit ladder A/D converter has input 101001. The output is (assume 0 = 0 V and 1 = 10 V)
A.	4.23
B.	6.41
C.	5.52
D.	9.23
Answer» C. 5.52

Discussion

840.	With the switch in STOP position, Y will be equal to
A.	0
B.	1
C.	CLK
D.	none of these
Answer» C. CLK

Discussion

841.	The logic circuit in the given figure realizes the function
A.	(A + B + C) (D E)
B.	(A + B + C) (D E)
C.	(A + B + C) (D E)
D.	(A + B + C) (D E)
Answer» E.

Discussion

842.	The microprograms provided by a manufacturer to be used on his microprogrammed computer are generally called
A.	software
B.	network
C.	firmware
D.	hardware
Answer» D. hardware

Discussion

843.	ECL is a saturating logic.
A.	1
B.
Answer» C.

Discussion

844.	A parity detector can detect
A.	single error only
B.	single error or odd number of errors
C.	two errors
D.	single or two errors
Answer» C. two errors

Discussion

845.	If interrupt service request have been received from all of the following interrupts, then which one will be serviced last?
A.	RST 5.5
B.	RST 6.5
C.	RST 7.5
D.	None of these
Answer» B. RST 6.5

Discussion

846.	Read the following statements The circuitry of ripple counter is more complex than that of synchronous counter.The maximum frequency of operation of ripple counter depends on the modulus of the counter.The maximum frequency of operation of synchronous counter does not depend on the modulus of the counter. Which of the above statements are correct?
A.	1 only
B.	1, 2
C.	1, 2, 3
D.	2, 3
Answer» E.

Discussion

847.	CMOS is extensively used in
A.	pocket calculators
B.	digital wrist watches
C.	satellites
D.	all of the above
Answer» E.

Discussion

848.	If modulus is less than 2N, some states of the counter are skipped by using NAND gates.
A.	1
B.
Answer» B.

Discussion

849.	The amplifier used in miller voltage sweep should have a gain of
A.	-‚àû
B.	1
C.	+‚àû
D.	-1
Answer» B. 1

Discussion

850.	The characteristic equation of flip-flop gives the next state QN + 1 in terms of present state QN and the inputs. Which one of the following is the characteristic equation of J - K flip-flop?
A.	QN+1 = JQN + KQN
B.	QN+1 = J + KQN
C.	QN+1 = KQN + JQN
D.	QN+1 = K + JQN
Answer» B. QN+1 = J + KQN

Discussion

Explore topic-wise MCQs in Electronics & Communication Engineering.

How many and what are the machine cycles needed for execution of MOV D, C?

Vectored interrupt is an interrupt that takes the program to a vector location. TRAP vectors to 0024 FI, RST 7.5 to 003 CH, RST 6.5 to 0034 H and

The value of program counter of 6800 at power on are after reset is

In 8085 microprocessor, what is the length of SP (stack) pointer?

In the given figure shows a 3 bit shift register using TTL flip flops. Initially all the flip flops are set to 0 state. After 8 clock pulses

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By placing an inverter between both inputs of an S-R flip-flop, the resulting flip-flop becomes

What will be the maximum conversion time in 6 bit dual slope A/D converter uses a reference of -6v and a 1 MHz clock. It uses a fixed count of 40 (101000).

When two 4 bit parallel adders are cascaded we get

Assuming accumulator contain A 64 and the carry is set (1). What will accumulator (A) and carry (CY) contain after ANA A?

The series 54 H/74 H denotes

The output of the circuit shown below will be of the frequency

In a mod-12 counter the input clock frequency is 10 kHz. The output frequency is

For edge triggering in flip flops, manufacturers use

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The MOS symbol shown indicates that It is depletion typeIt is enhancement typeIt is channelIt is P-channelElectrons flow from s to DHoles flow from D to s The true statements are

The contents of the program counter after the call operation point to the first instruction on the

Which of the following statements defines a full adder?

The noise margin of a TTL gate is about

The radix of a hexadecimal system is

The logic represented by the abbreviation ECL is

As compared to TTL, ECL has

In 8085 microprocessor, the RST 5.5 interrupt service routine start from location

The minimum number of 2 input NAND gates required to implement Boolean function A B C is A, B, C are available is

The minimum number of NAND gates required to implement the Boolean function A +AB + ABC is equal to

What is the decimal equivalent of the binary number shown in fourth row?

A microprocessor with a 16 bit address bus is used in a linear memory selection configuration. Address bus lines are directly uses as chip selects of memory chips with 4 memory chips the maximum addressable memory space is

What kind of signal does the times produce?

Which of the following pairs of octal and binary numbers are not equal?

A 10 bit D/A converter gives a maximum output of 10.23 V. The resolution is

A sequence detector is required to give a logical output of 1 whenever the sequence 1011 is detected in the incoming pulse stream. Minimum number of flip-flops needed to built the sequence detector is

In a digital system, the maximum clock frequency that can be used with Master/Slave Clocked flip-flops having total propagation delay of 200 Œºsec is

Out of SAM and RAM

What is the normal range of analog input voltage?

In 2's complement form, - 2 is

A ripple counter has 4 bits and uses flip flops with propagation delay time of 25 ns. The maximum possible time for change of state will be

EEPROM is also known as

Which binary addition is incorrect?

A 6 bit ladder A/D converter has input 101001. The output is (assume 0 = 0 V and 1 = 10 V)

With the switch in STOP position, Y will be equal to

The logic circuit in the given figure realizes the function

The microprograms provided by a manufacturer to be used on his microprogrammed computer are generally called

ECL is a saturating logic.

A parity detector can detect

If interrupt service request have been received from all of the following interrupts, then which one will be serviced last?

CMOS is extensively used in

If modulus is less than 2N, some states of the counter are skipped by using NAND gates.

The amplifier used in miller voltage sweep should have a gain of

The characteristic equation of flip-flop gives the next state QN + 1 in terms of present state QN and the inputs. Which one of the following is the characteristic equation of J - K flip-flop?