mathematics and computer hardware questions...

CIS018-1 Fundamentals of Computer Studies

MATHEMATICS AND COMPUTER HARDWARE QUESTIONS AND ANSWERS - REVISION

Question The decimal number +125 can be represented in signed binary as:Answer 01111101

10000010

11111001

None of the above

Question The decimal number -36 is expressed in the 2’s complement form as:Answer 11011100

11011011

01011011

None of the above

Question The inputs to a full-adder are A=1, B=1 and Cin=0. The outputs areAnswer Sum=0, Cout=1

Sum=1, Cout=0

Sum=1, Cout=1

None of the above

Question The sum of 1010+10111 equalsAnswer 110001

101101

111010

101111

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Question The purpose of the clock input to a flip-flop is toAnswer cause the output to change state dependent on the inputs

clear the device

set the device

always cause the output to change states

Question For an edge-triggered D flip-flopAnswer a change in the state of the flip-flop can occur only at a clock pulse

edge

the state that the flip-flop goes to depends on the D input

the output follows the input at each clock pulse edge

all of these answers

Question The storage cell in a SRAM is a Answer flip-flop

fuse

capacitor

magnetic domain

Question The bit capacity of a memory that has 10 bit long address and can store 8 bits at each address is

Answer 8192

1024

18

80

Question How many bits are required in an address bus for a memory of 1024 bytes?

Answer 10

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8

11

None of the other answers is correct

Question How many gates would it require to implement the Boolean formula

A(B+C) in the straightforward way (without transformations or

simplifications)?

Answer 4

5

3

6

Question A two-input AND gate has the following inputs

Which of the following is its output?

Answer

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Question A two-input OR gate has the following inputs:


Answer

Question A two-input EX-OR gate has the following inputs:


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Answer

Question For the circuit given below, what is B and C respectively?

Answer B=A and C=A

B=A and C=A

B=A and C=A

B=A and C=A

Question The benefit of the assembly language is that it is:Answer Fast and efficient

Can be used on any processor

Easier to write programs

None of the above

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Question The benefits of RISC design simplicity areAnswer Smaller chip and pin count

Smaller programs

Easy programming

All of the above

Question The states of the flags are stored in the ________Answer Status register

Working register

Instruction register

Flag register

Question The newer Microchip dsPIC is a ________ controller with digital signal processing capability

Answer 32 bits

16 bits

8 bits

Question What is the size of the data bus in a PIC16F684?Answer 4

8

12

16

Question The difference of 101-011 equalsAnswer 010

100

101

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011

Question The Boolean expression A.1 is equal toAnswer A

0

1

None of the above

Question The following Boolean identity is correct? A + 1 = 1

Answer True

False

Question The Boolean expression A + 1 is equal toAnswer A

0

1

None of the above

Question Which of the following expressions is equivalent to A(A + B)?Answer A + B

0

1

None of the above

Question The Boolean expression BC + ABC is equivalent to Answer BC

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ABC

BC


Question What is one disadvantage of an R-S flip flop?Answer It has only a single output

It has no CLOCK input

It has no Enable input

It has an invalid input state

Question When both inputs of a J-K pulse-triggered FF are high, and the clock cycles, the output will _________

Answer be invalid

toggle

not change

remain unchanged

Question The function ABCD can be decoded with ______Answer Two 2-input OR gates and two inverters

Two 2-input OR gates and one inverter

One 4-input AND gate and one inverter

One 4-input AND gate

Question The relationship between a NOR gate and an AND gate is expressed by ________

Answer AB = A + B

A + B = A B

AB = A + B

None of the above

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Question The commutative law of Boolean algebra states that A + B = A BAnswer True

False

Question The output of a NOR gate is HIGH only when all inputs are HIGHAnswer True

False

Question The output of a NAND gate is LOW only when all inputs are HIGHAnswer True

False

Question Any Boolean Expression can be implemented using only NAND gatesAnswer True

False

Question It is possible to implement any Boolean expression using only OR gates

Answer True

False

Question 1’s complement of a binary number is obtained by adding 1 to its 2’s complement

Answer True

False

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Question The output of an OR gate is LOW only when at least one input is LOW

Answer True

False

Question When referring to instructions words, a mnemonic is:Answer A short abbreviation for the operand address

Shorthand for machine language

A short abbreviation for the operation to be performed

A short abbreviation for the data word stored at the operand address

Question What is the difference between a microcontroller and microprocessor?

Answer A microcontroller does not have a CPU whereas a microprocessor has a CPU

A microcontroller has no memory whereas a microprocessor has memory

A microcontroller contains the CPU, memory and I/O in a single chip whereas in a microprocessor the components may be in different chips

None of the above

Question What is TRISA in the PIC?Answer input port

output port

memory

data direction register

Question What is the primary function of a register?Answer counting

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encoding

data storage (memory)

decoding

Question The application of DeMorgan’s theorems will reduce the expression X

= (A + B + C) + (A + B + C) + (AB + C) to which sum-of-products

expression?

Answer X = (A + B + C) + ABC + ABC

X = (A + B + C) + (ABC) + (ABC)

X = ABC + ABC + AC + BC

X = ABC + ABC + ABC

Question The output of an OR gate with inputs A, B, and C is a 1 whenAnswer A=1, B=1, C=1

A=0, B=0, C=1

A=1, B=0, C=1

All of them

None of them

Question The Karnaugh map below represents the expression, X = ACD + AB(CD + BC)

C D C D C D C D

A B 0 0 0 0

A B 0 0 1 1

A B 0 0 0 1

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A B 0 0 0 1

Answer True

False

Question Which of the following SoPs corresponds to the Karnaugh map below?

BC BC BC BC

A\BC 00 01 11 10

A 0 1 1 1 1

A 1 1 0 0 1

Answer A + C

AC

C + AC

B + C


B B

A\B 0 1

A 0 1 1

A 1 0 0

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Answer A

A

B

B

Question How many gates would it require to implement Boolean formula

A (B + C) in the straightforward way (without transformations or

simplifications)?

Answer 5

4

3

6

Question The output of an AND gate with inputs A, B, and C is a 1 whenAnswer A=1, B=1, C=1

A=1, B=0, C=1

A=0, B=1, C=0

All are correct

Question Which of the following is equivalent to (A + B)C?

AnswerAC + BC


AB + C

AB + C

Question Given the circuit below, what is the minimum number of gates you

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can use to implement this function? (Assume 2, 3 and 4-input gates are available)

Answer 2

3

1

4

Question Which of the following is equivalent to A(BC + AB + AC)?

AnswerBC

A + BC

A . B + C


Question Which of the following expressions is represented by the following Karnaugh map?

C C

A B 1 0

A B 0 1

A B 0 1

A B 1 0

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AnswerAC + AC

BC + BC

B + B

AC + AC + BC + BC


B B

A\B 0 1

A 0 1 1

A 1 0 1

AnswerA + B

AB

A + AB

AB + B

Question Which of the following expressions is equivalent to A.A.B?Answer A.B

A

1

None

Question The binary number 11012 is equal to the decimal numberAnswer 13

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49

11

3

Question When performing binary addition using the 2’s complement method, an overflow is indicated by a (n) _________

Answer Negative sign

Incorrect sign bit

Incorrect polarity

Incorrect sum

Question Given the circuit below, what is the minimum number of gates you can use to implement this function? (Assume 2, 3 and 4-input gates are available)

Answer 2

3

1

4

Question The number of values that can be assigned to a bit areAnswer 2

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1

10

0

Question What is the base (radix) for octal numbers?Answer 8

16

7

6

Question The output of an AND gate is LOW only when all inputs are LOWAnswer True

False

Question What is the BCD form of 438?Answer 1010000111000

010000111000

000110110110

0100000110100

Question The highest decimal value that can be represented by a 4-bit binary number is ____________

Answer 32

8

7

15

Question Which of the following expressions is equivalent to (A + B) + A?

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Answer A + B

0

A

None

Question Which of the following expressions is equivalent to A.B + A?Answer A

B

1

None

Question Which of the following expressions is equivalent to A.C.B.D + A?Answer A + B + C + D

A.B.C.D

A

None

Question Which of the following is equivalent to (A + C)(B + C)(B + D)(A + D)?Answer AD + BC

A + B + C +D

AB + CD

ABC + BCD + ACD + ABD

Question For an OR gate, if any of the input is high (1), output is high (1)Answer True

False

Question Which of the following is the hexadecimal representation of binary number 1101001101?

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Answer D31

34D

C4D

D34

Question Addition in Boolean Algebra is not equivalent to OR function.Answer True

False

Question Which of the following is the binary representation of decimal number 151?

Answer 10110001

0151

11011

10010111

Question What is the hex equivalent of the binary number 101010112

Answer 8516

E816

AB16

9B16

Question Which of the following binary numbers is equal to 010100102 + 001100012?

Answer 011100112

100000112

000000112

100000012

Question Which of the following binary numbers is equal to 11112 + 11112?

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Answer 111102

None of the answers is correct

100002

11112

Question Which of the following is the decimal representation of hexadecimal number 12316?

Answer 80110

29110

12310

413110

Question Which of the following is the number that is represented by 11101001 in 8-bit 2’s complement form?

Answer 233

-9

9

-23

Question Convert the decimal integer 27 to binaryAnswer 11011

101111

10110


Question What is the decimal equivalent of the binary integer 1101?Answer 13

12

9

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15

Question Convert the binary integer 1110001 to its hexadecimal equivalentAnswer E1H

F2H

71H


Question Convert the binary integer 1010010 to its octal equivalentAnswer 1228

828

978

5108

Question Convert the decimal number 463 into its BCD formAnswer 010001100011

000111001111

001001100010

000111001110

Question Which of the following is full-form of ALU?Answer Arithmetic and Logic Unit

Arithmetic Last Unit

Anti-Logic Unit

Arbitration Logic Unit

Question In computing, what does MSB stand for?Answer Most Significant Bit

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Most Significant Byte

Most Simple Byte

Most Structured Byte

Question How many cells are there in a 3-variable Karnaugh map?Answer 8

6

4

3

Question What is the decimal equivalent of the largest 8-bit binary integer?Answer 256

512

255

511

Question Which of the following are referred to as ‘Universal Gates’?Answer NAND and NOR

AND, OR and NOT

XOR and XNOR


Question Which of the following is the correct truth table of a NOR gate?

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Answer

Question A general computer requires:Answer CPU, Memory and I/O units

Control Unit, CPU, Memory and I/O units

ALU, CPU and Memory


Question What is the sum of 10012 + 10102?

Answer 100002

111102

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111112

Question Which of the following is the 2’s complement of 0000 (4-bit representation is assumed)?

Answer 0000

1110

0001

1101

Question What are the three basic logic operators?Answer AND, OR and NOT

AND, OR and NAND

NAND, NOR and XOR

XOR, XNOR and NOT

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Question Which logic operation can you relate to the following operations?

i. The light is ON if SW1 is closedii. The light is ON if SW2 is closediii. The light is OFF if both SW1 and SW2 are openiv. The light is ON if both SW1 and SW2 are closed

Answer AND operation

OR operation

XOR operation

NAND operation

Question A logic circuit requires HIGH on all its inputs to make the output HIGH. Which logic operation does this represent?

Answer AND

OR

XOR

NOT

Question Consider an 8-bit register that has been RESET. If you transfer 0101 serially into the register, beginning with a 1 and shifting to the right, what will the total content of the register be as soon as the fourth bit is stored.?

Answer A0H

50H

05H

0AH

Question Which of the following is equivalent to hexadecimal integer A1416 in binary?

Answer 101000010100

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010110100

11011111

None if the other answers is correct

Question Convert -27 to binary using 2’s complement representation. Answer 01100101

00011011

11100101

10011011

Question Which of the following is the decimal representation of binary number 1000101?

Answer 69

1000101.0

81

37

Question Which of the following is the binary representation of decimal number 101110?

Answer 10112

101110

1111110011

111110011

Question What is the binary equivalent of 4F16?

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Answer 10011112

10011002

100011112

None

Question The decimal number -36 is expressed in the 2’s complement form asAnswer 11011100

11011011

01011011

None of the above

Question In the 2’s complement form, the binary number 10010011 is equal to the decimal number

Answer -109

+109

-19

+19

Question Which of the following is the hexadecimal representation of decimal number 7522?

Answer 26131

11362

1D62

26D1

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Question What is the value of the sum 225 + 345?Answer 445

1215

1115

1005

Question Which of the following expressions is equivalent to A.A.B + B?Answer A

B

1

None

Question An OR gate has an output that is opposite of an NOR gateAnswer True

False

Question Which of the following expressions is equivalent to A.(A + B) + A?Answer A + B

0

A

None

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Question Which of the following expressions is represented by the following Karnaugh map?

C C

A B 1 0

A B 0 1

A B 0 1

A B 0 0

Answer AC + AC

BC + C

ABC + BC

BC + BC

Question Which of the following 4 bits must appear in the lower row of the Karnaugh map to correspond to the truth table below?

A B C Function0 0 0 10 0 1 10 1 0 10 1 1 11 0 0 01 0 1 11 1 0 01 1 1 1

BC BC BC BC

A\BC 00 01 11 10

A 0 1 1 1

A 1

Answer 0 0 1 1

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0 1 1 0

1 1 0 1

1 0 1 0

Question Which formula describes the circuit shown below?

Answer (A + B)CD

C(A + B) + D

AB + C + D

ABCD

Question The following is the truth table for which gate?

A B X0 0 00 1 11 0 11 1 1

Answer OR gate

AND gate

NAND gate

NOR gate

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Question A gate that gives 0 (low) when both its inputs are 1 (high) is a _________ gate.

Answer

Question Select the correct statement from the followingAnswer Flash memory uses a flashing beam of light to store data

Dynamic RAMs must be periodically refreshed to retain data

RAM is Random Address Memory

Optical storage devices employ ultraviolet light

Question How many bits are there in a byteAnswer 8

6

10

2

Question A byte-organised memory hasAnswer 8 data output lines

16 output data lines

1 data output line

None of the above

Question RAM isAnswer Volatile memory

Random address memory

Stored data is not lost if power is removed

All answers are correct

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NOR or NAND or XOR


Question What is the binary equivalent of 178?Answer 1011112

11112

100012

None of the above

Question Find the output of an 8- bit AND gate for the following binary inputs

A=01011100B=11110101

Answer 1010100

Question Find the output of an 8-bit OR gate for the following binary inputs

A=01011100B=11110101

Answer 11111101

Question A circle, or “bubble”, on a distinctive-shape logic symbol indicates a logic inversion

Answer True

False

Question In binary multiplication, 1 x 1 = __________Answer 0 with a carry of 1

1 with a carry of 1

1

0

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Question The Boolean expression for the symbol in the figure below is _______

Answer X = (A + B)(B + C)

X = A + B + C + D

X = AB + BC

X = ABCD

Question The symbol shown in the figure below is a(n) ________ gate

Answer Exclusive-OR

AND

Exclusive-NOR

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OR

Question Which circuit in the figure below represents the NAND implementation of a NOR function?

Answer Figure A

Figure B

Figure C

Figure D

Question Occasionally, a particular logic expression will be of no consequence in the operation of a circuit such as in a BCD-to-decimal converter. These result in _____________ terms in the Karnaugh map and can be treated as either ___________ or __________

Answer Don’t care, 1s, 0s

Duplicate, 1s, 0s

Spurious, ANDs, ORs

Spurious, 1s, 0s

Question How many gates, including inverters, are required to implement the

equation, X = A + AB + AB, after it is simplified using Boolean

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algebra?

Answer 1

2

3

4

Question Which single multi-input gate can be used to implement the Boolean

formula A . B . C?

Answer NOR

AND

NAND

OR

Question Which single (only one) multi-input gate can be used to implement

the Boolean formula A . B . C?

Answer a 3-input NOR gate

a 3-input NAND gate

a 3-input XOR gate

a 3-input OR gate

Question Which circuit in the figure below represents the NAND implementation of an AND gate?

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Answer Figure A

Figure B

Figure C

Figure D

Question In using the 2’s-complement system of subtraction, a negative number in the subtrahend would ultimately be changed to:

Answer A negative number in true binary form

A positive number in true binary form

Question Which of the following lists memory devices from the most complex and expensive, to the least complex and expensive?

Answer Flash, EPROM, EEPROM, PROM

PROM, Flash, EEPROM, EPROM

EEPROM, Flash, EPROM, PROM

EEPROM, PROM, Flash, EPROM

Question For the network shown below, the Boolean expression for X is ________

Answer (AC + BC)D

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((A + B).C) + D

A + BC + D

D(A + B + C)

Question An assembler is used to ________Answer Convert assembly language to machine code

Convert the assembly language from one processor to the assembly language for another processor

Convert a high-level language to assembly language

Write and edit assembly language programs

Question An advantage of assembly language programs is _________Answer They typically run faster than programs written in a higher level

language

They can use the same compiler tools as high-level languages

They can run on any processor

They are well suited for large and complex applications

Question A complier ________Answer Allows machine code for one processor to run on another processor

Converts machine code into assembly language

Converts assembly language into a high-level language

Converts a high-level language to machine code

Question How many I/O ports are in the PIC (16F684)?

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Answer 1

2

3

4

Question You are given a task to write a program for PIC 16F684 in assembly language to light-up some of the LEDs. Which port will you need to use in the program?

Answer Port A

Port B

Question In a microcontroller, which of the following registers is used for temporarily storing the operands/result of an ALU operation?

Answer Working register


Program counter

I/O register

Question Match the following names of circuits or gates with the operations they perform

Answer OR (Boolean sum) gate Finds the maximum of two input bits

Half-Adder Finds the sum of two input bits

Full-Adder Finds the sum of three input bits

Parallel Adder Finds the sum of two n-bit input numbers

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Question How many instructions are there in a PIC?Answer 35

74

108

None of the above

Question The Control Unit decodes the instruction and generates control signals for registers

Answer True

False

Question The assembler encounters the following instruction in the PIC16F684 program

MOVF R, W

What action would the assembler take?Answer Contents of register W are moved to R

Contents of register R are moved to W

Contents of register F are moved to R

Contents of register F are moved to W

Question Which register is used to address program memory?Answer Status register


Working register

Program counter

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Question In a processor, the address of the next instruction to be executed by the CPU is stored in the

Answer Stack pointer


Working register

Program counter

Question Which of the following bus(es) connect a CPU to its memoryAnswer Address bus

Data bus

Control (Read/Write) bus

All of the mentioned buses

Question Which register is a dedicated temporary storage register that simply stores the current instructions to be executed?

Answer Status register


I/O register

Working register

Question How many bits are required to program the PORTA/PORTC in the Op-code?

Answer 24

18

12

6

Question Before writing down assembly language instructions for the PIC, you need to give some instructions to the assembler. These instructions are referred to as

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Answer the BIOS

Executable instructions

System programs

Assembler directives

Question Information given to an assembler such as where to begin executing instructions is provided by

Answer the BIOS

Executable instructions

System programs

Assembler directives

Question Select one of the basic functional blocks of a microcomputer: Answer ALU

Microprocessor

Hard drive

None of the above

Question PIC16F684 has memory divided into blocks. What are the two memory blocks called?

Answer Program and instruction memory

Data and program memory

Instructions and data memory

Program and Flash memory

Question The 1’s complement of 10111001 isAnswer 01000110

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01000111

11000110

10111001

Question The 2’s complement of 11001000 isAnswer -109

+109

-19

+19

Question Select the correct statement from the following:Answer The 2’s complement of the binary number 0001 is 1111

The 1’s complement of the binary number 0101 is 1011

BCD stands for Binary Code for Digital

LSB stands for Lowest Single Bit

Question Choose a correct statement from the followingAnswer The decimal number system is a weighted system with ten digits

LSB stand for lowest single bit

In binary, 1 + 1 = 2

The right-most bit in a signed binary number is the sign bit

Question In the 2’s complement form, the binary number 01110101 is equal to:Answer +117

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-117

+10

-10

Question In the 2’s complement form, the binary number 10010011 is equal to the decimal number

Answer -109

+109

-19

+19

Question A 4-bit parallel adder can addAnswer Two 4-bit binary numbers

Two 2-bit binary numbers

Four bits at a time

Four bits in a sequence

Question Select the correct statement from the following:Answer When the two input bits are both 1 and the carry bit is a 1, the sum

output of a full adder is 1

A full adder adds three bits and produces two outputs

Both statements are correct

Both statements are false

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Question Select the correct statement from below:Answer A half-adder adds two binary bits

A half-adder has a sum output only

Two 4-bit numbers can be added using two full-adders

All are incorrect statements

Question Select the correct statement from below:Answer A data byte consists of eight bits

A memory cell can store a byte of data

The read operation always erases the data byte

ROM is a Random Output memory

Question A half-adder is characterised by:Answer Two inputs and two outputs

Three inputs and two outputs

Two inputs and one output

None of the above

Question Data is stored in RAM during theAnswer Write operation

Read operation

Enable operation

Addressing operation

Question For a gated D latch, the Q output always equals the D input

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Answer During the enable pulse

Before the enable pulse

When D = 1

When D = 0

Question For an edge-triggered D flip-flopAnswer a change in the state of the flip-flop can occur only at a clock pulse

edge

the state that the flip-flop goes to depends on the D input

the output follows the input at each clock pulse edge

all of these answers

Question If a S-R latch has a 1 on the S input and a 0 on the R input and hen the S input goes to 0, the latch will be

Answer Set

Reset

Clear

Invalid

Question Select the correct statement from below:Answer A data byte consists of 8 bits

A memory cell can store a byte of data

The read operation always erases the data byte

ROM is a Random Output Memory

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Question DRAM must beAnswer Refreshed periodically

Programmed before each use

Always enabled

Replaced periodically

Question A memory with 256 addresses hasAnswer 256 address lines

8 address lines

6 address lines

9 address lines

Question Select the correct statement from followingAnswer A latch has two stable states

A latch is considered to be in SET state when the Q output is LOW

An edge triggered D flip-flop changes state whenever the D input changes

All are correct

Question ROM is aAnswer Non-volatile memory

Volatile memory

Read/write memory

Byte-organised memory

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