AKTU MCQ

# Top 150+ Computer Organization and Architecture MCQ Questions

COA INTRODUCTION: Computer Organization and Architecture is the study of internal working, structuring and implementation of a computer system. Architecture in computer system, same as anywhere else, refers to the externally visual attributes of the system.

Top 150+ COA MCQ | Computer Organization and Architecture Multiple Choice Questions :
In Reverse Polish notation, expression AB+CD is written as
(A) ABCD+
(B) ABCD+
(C) ABCD+
(D) ABCD+

Ans: A

SIMD represents an organization that __.
(A) refers to a computer system capable of processing several programs at the same
time.
(B) represents organization of single computer containing a control unit, processor
unit and a memory unit.
(C) includes many processing units under the supervision of a common control unit
(D) none of the above.

Ans: C

Floating point representation is used to store
(A) Boolean values
(B) whole numbers
(C) real integers
(D) integers

Ans: C

Suppose that a bus has 16 data lines and requires 4 cycles of 250 nsecs each to
transfer data. The bandwidth of this bus would be 2 Megabytes/sec. If the cycle time
of the bus was reduced to 125 nsecs and the number of cycles required for transfer
stayed the same what would the bandwidth of the bus?
(A) 1 Megabyte/sec
(B) 4 Megabytes/sec
(C) 8 Megabytes/sec
(D) 2 Megabytes/sec
Ans: D

Assembly language
(A) uses alphabetic codes in place of binary numbers used in machine language
(B) is the easiest language to write programs
(C) need not be translated into machine language
(D) None of these

Ans: A

In computers, subtraction is generally carried out by
(A) 9’s complement
(B) 10’s complement
(C) 1’s complement
(D) 2’s complement

Ans: D

The amount of time required to read a block of data from a disk into memory is
composed of seek time,
rotational latency,
and transfer time.
Rotational latency
refers to
(A) the time its takes for the platter to make a full rotation
(B) the time it takes for the read-write head to move into position over the
appropriate track
(C) the time it takes for the platter to rotate the correct sector under the head
(D) none of the above
Ans: A

What characteristic of RAM memory makes it not suitable for permanent storage?
(A) too slow
(B) unreliable
(C) it is volatile
(D) too bulky
Ans: C

Computers use addressing mode techniques for _.
(A) giving programming versatility to the user by providing facilities as pointers to
memory counters for loop control
(B) to reduce no. of bits in the field of instruction
(C) specifying rules for modifying or interpreting address field of the instruction
(D) All the above
Ans: D

The circuit used to store one bit of data is known as
(A) Register
(B) Encoder
(C) Decoder
(D) Flip Flop
Ans: D

(2FAOC) 16 is equivalent to
(A) (195 084) 10
(B) (001011111010 0000 1100) 2
(C) Both (A) and (B)
(D) None of these
Ans: B

The average time required to reach a storage location in memory and obtain its contents is called the
(A) seek time
(B) turnaround time
(C) access time
(D) transfer time
Ans: C

Which of the following is not a weighted code?
(A) Decimal Number system
(B) Excess 3-cod
(C) Binary number System
(D) None of these
Ans: B

The idea of cache memory is based
(A) on the property of locality of reference
(B) on the heuristic 90-10 rule
(C) on the fact that references generally tend to cluster
(D) all of the above
Ans: A

Which of the following is lowest in memory hierarchy?
(A) Cache memory
(B) Secondary memory
(C) Registers
(D) RAM
(E) None of these
Ans (B) Secondary memory

The addressing mode used in an instruction of the form ADD X Y, is
(A) Absolute
(B) indirect
(C) index
(D) none of these
Ans: C

If memory access takes 20 ns with cache and 110 ns with out it, then the ratio (cache uses a 10 ns memory) is
(A) 93%
(B) 90%
(C) 88%
(D) 87%
Ans: B

In a memory-mapped I/O system, which of the following will not be there?
(A) LDA
(B) IN
(D) OUT
Ans: A

In a vectored interrupt.
(A) the branch address is assigned to a fixed location in memory.
(B) the interrupting source supplies the branch information to the processor through
an interrupt vector.
(C) the branch address is obtained from a register in the processor
(D) none of the above
Ans: B

Von Neumann architecture is
(A) SISD
(B) SIMD
(C) MIMD
(D) MISD

Ans: A

The circuit used to store one bit of data is known as
(A) Encoder
(B) OR gate
(C) Flip Flop
(D) Decoder
Ans: C

Cache memory acts between
(A) CPU and RAM
(B) RAM and ROM
(C) CPU and Hard Disk
(D) None of these
Ans: A

Write Through technique is used in which memory for updating the data
(A) Virtual memory
(B) Main memory
(C) Auxiliary memory
(D) Cache memory
Ans: D

Generally Dynamic RAM is used as main memory in a computer system as it
(A) Consumes less power
(B) has higher speed
(C) has lower cell density
(D) needs refreshing circuitary
Ans: B

In signed-magnitude binary division, if the dividend is (11100) 2 and divisor is (10011) 2 then the result is
(A) (00100) 2
(B) (10100) 2
(C) (11001) 2
(D) (01100) 2
Ans: B

Virtual memory consists of
(A) Static RAM
(B) Dynamic RAM
(C) Magnetic memory
(D) None of these
Ans: A

In a program using subroutine call instruction, it is necessary
(A) initialise program counter
(B) Clear the accumulator
(C) Reset the microprocessor
(D) Clear the instruction register
Ans: D

A Stack-organised Computer uses instruction of
Ans: C

If the main memory is of 8K bytes and the cache memory is of 2K words. It uses associative mapping. Then each word of cache memory shall be
(A) 11 bits
(B) 21 bits
(C) 16 bits
(D) 20 bits
Ans: C

30 A-Flip Flop can be converted into T-Flip Flop by using additional logic circuit
(A) n TQD =•
(B) T D =
(C) D = T . Q n
(D) n TQD =?

Ans: D

Computer Organization and Architecture mcq
Logic X-OR operation of (4ACO) H & (B53F) H results
(A) AACB
(B) 0000
(C) FFFF
(D) ABCD
Ans: C

When CPU is executing a Program that is part of the Operating System, it is said to be in
(A) Interrupt mode
(B) System mode
(C) Half mode
(D) Simplex mode
Ans: B

An n-bit microprocessor has
(A) n-bit program counter
(C) n-bit ALU
(D) n-bit instruction register
Ans: D

Cache memory works on the principle of
(A) Locality of data
(B) Locality of memory
(C) Locality of reference
(D) Locality of reference & memory
Ans: C

The main memory in a Personal Computer (PC) is made of

(A) cache memory.
(B) static RAM
(C) Dynamic Ram
(D) both (A) and (B) .
Ans: D

In computers, subtraction is carried out generally by

(A) 1’s complement method
(B) 2’s complement method
(C) signed magnitude method
(D) BCD subtraction method
Ans: B

PSW is saved in stack when there is a
(A) interrupt recognised
(B) execution of RST instruction
(C) Execution of CALL instruction
(D) All of these
Ans: A

The multiplicand register & multiplier register of a hardware circuit implementing booth’s algorithm have (11101) & (1100). The result shall be
(A) (812) 10
(B) (-12) 10
(C) (12) 10
(D) (-812) 10
Ans: A

The circuit converting binary data in to decimal is
(A) Encoder
(B) Multiplexer
(C) Decoder
(D) Code converter
Ans: D

A three input NOR gate gives logic high output only when
(A) one input is high
(B) one input is low
(C) two input are low
(D) all input are high
Ans: D

n bits in operation code imply that there are _ possible distinct operators
(A) 2n
(B) 2n
(C) n/2
(D) n2
Ans: B

_ register keeps tracks of the instructions stored in program stored in memory.
(B) XR (Index Register)
(C) PC (Program Counter)
(D) AC (Accumulator)
Ans: C

Memory unit accessed by content is called
(B) Programmable Memory
(C) Virtual Memory
(D) Associative Memory
Ans: D

‘Aging registers’ are
(A) Counters which indicate how long ago their associated pages have been
referenced.
(B) Registers which keep track of when the program was last accessed.
(C) Counters to keep track of last accessed instruction.
(D) Counters to keep track of the latest data structures referred.
Ans: A

The instruction ‘ORG O’ is a
(A) Machine Instruction.
(B) Pseudo instruction.
(C) High level instruction.
(D) Memory instruction.
Ans: B

Translation from symbolic program into Binary is done in
(A) Two passes.
(B) Directly
(C) Three passes.
(D) Four passes.
Ans: A

47 A floating point number that has a O in the MSB of mantissa is said to have
(A) Overflow
(B) Underflow
(C) Important number
(D) Undefined

Ans: B

The BSA instruction is
(A) Branch and store accumulator
(B) Branch and save return address
(D) Branch and show accumulator
Ans: B

State whether True or False.
(i) Arithmetic operations with fixed point numbers take longer time for execution as
compared to with floating point numbers.
Ans: True.

(ii) An arithmetic shift left multiplies a signed binary number by 2.

Ans: False.

Logic gates with a set of input and outputs is arrangement of
(A) Combinational circuit
(B) Logic circuit
(C) Design circuits
(D) Register
Ans: A

MIMD stands for
(A) Multiple instruction multiple data
(B) Multiple instruction memory data
(C) Memory instruction multiple data
(D) Multiple information memory data
Ans: A

52 A k-bit field can specify any one of
(A) 3k registers
(B) 2k registers
(C) K2 registers
(D) K3 registers

Ans: B

53 The time interval between adjacent bits is called the
(A) Word-time
(B) Bit-time
(C) Turn around time
(D) Slice time

Ans: B

54 A group of bits that tell the computer to perform a specific operation is known as
(A) Instruction code
(B) Micro-operation
(C) Accumulator
(D) Register

Ans: A

55 The load instruction is mostly used to designate a transfer from memory to a processor register known as
(A) Accumulator
(B) Instruction Register
(C) Program counter

Ans: A

56 The communication between the components in a microcomputer takes place via the address and
(A) I/O bus
(B) Data bus
(D) Control lines

Ans: B

57 An instruction pipeline can be implemented by means of
(A) LIFO buffer
(B) FIFO buffer
(C) Stack
(D) None of the above

Ans: B

58 Data input command is just the opposite of a
(A) Test command
(B) Control command
(C) Data output
(D) Data channel

Ans: C

59 A microprogram sequencer
(A) generates the address of next micro instruction to be executed.
(B) generates the control signals to execute a microinstruction.
(C) sequentially averages all microinstructions in the control memory.
(D) enables the efficient handling of a micro program subroutine.

Ans: A

60 . A binary digit is called a
(A) Bit
(B) Byte
(C) Number
(D) Character

Ans: A

61 A flip-flop is a binary cell capable of storing information of
(A) One bit
(B) Byte
(C) Zero bit
(D) Eight bit

Ans: A

62 The operation executed on data stored in registers is called
(A) Macro-operation
(B) Micro-operation
(C) Bit-operation
(D) Byte-operation

Ans: B

63 MRI indicates
(A) Memory Reference Information.
(B) Memory Reference Instruction.
(C) Memory Registers Instruction.
(D) Memory Register information

Ans: B

64 Self-contained sequence of instructions that performs a given computational task is called
(A) Function
(B) Procedure
(C) Subroutine
(D) Routine

Ans: A

65 Microinstructions are stored in control memory groups, with each group specifying a
(A) Routine
(B) Subroutine
(C) Vector

Ans: A

66 An interface that provides a method for transferring binary information between internal storage and external devices is called
(A) I/O interface
(B) Input interface
(C) Output interface
(D) I/O bus

Ans: A

67 Status bit is also called
(A) Binary bit
(B) Flag bit
(C) Signed bit
(D) Unsigned bit

Ans: B

68 An address in main memory is called

Ans: A

69 If the value V(x) of the target operand is contained in the address field itself, the addressing mode is
(A) immediate.
(B) direct.
(C) indirect.
(D) implied.

Ans: B

70 can be represented in a signed magnitude format and in a 1’s complement format as
(A) 111011 & 100100
(B) 100100 & 111011
(C) 011011 & 100100
(D) 100100 & 011011

Ans: A

71 The instructions which copy information from one location to another either in the processor’s internal register set or in the external main memory are called
(A) Data transfer instructions.
(B) Program control instructions.
(C) Input-output instructions.
(D) Logical instructions.

Ans: A

72 .A device/circuit that goes through a predefined sequence of states upon the application of input pulses is called
(A) register
(B) flip-flop
(C) transistor.
(D) counter.

Ans: D

The performance of cache memory is frequently measured in terms of a quantity called
(A) Miss ratio.
(B) Hit ratio.
(C) Latency ratio.
Ans: C

The information available in a state table may be represented graphically in a
(A) simple diagram.
(B) state diagram.
(C) complex diagram.
(D) data flow diagram.
Ans: B

1. Content of the program counter is added to the address part of the instruction in order to obtain the effective address is called.
(C) register mode.
(D) implied mode.

Ans: A

1. An interface that provides I/O transfer of data directly to and form the memory unit and peripheral is termed as
(A) DDA.
(B) Serial interface.
(C) BR.
(D) DMA.

Ans: D

1. The 2s compliment form (Use 6 bit word) of the number 1010 is
(A) 111100.
(B) 110110.
(C) 110111.
(D) 1011.

Ans: B

1. A register capable of shifting its binary information either to the right or the left is called a
(A) parallel register.
(B) serial register.
(C) shift register.
(D) storage register.

Ans: C

1. What is the content of Stack Pointer (SP)?
(A) Address of the current instruction
(B) Address of the next instruction
(C) Address of the top element of the stack
(D) Size of the stack.

Ans: C

1. Which of the following interrupt is non maskable
(A) INTR.
(B) RST 7.5.
(C) RST 6.5.
(D) TRAP.

Ans: D

81 Which of the following is a main memory
(A) Secondary memory.
(B) Auxiliary memory.
(C) Cache memory.
(D) Virtual memory.

Ans: C

82 Which of the following are not a machine instructions
(A) MOV.
(B) ORG.
(C) END.
(D) (B) & (C) .

Ans: D

83 In Assembly language programming, minimum number of operands required for an instruction is/are
(A) Zero.
(B) One.
(C) Two.
(D) Both (B) & (C) .

Ans: A

84 The maximum addressing capacity of a micro processor which uses 16 bit database & 32 bit address base is
(A) 64 K.
(B) 4 GB.
(C) both (A) & (B) .
(D) None of these.

Ans: B

85 The memory unit that communicates directly with the CPU is called the
(A) main memory
(B) Secondary memory
(C) shared memory
(D) auxiliary memory.

Ans: A

86 The average time required to reach a storage location in memory and obtain its contents is called
(A) Latency time.
(B) Access time.
(C) Turnaround time.
(D) Response time.

Ans: B

State True or False
87 A byte is a group of 16 bits.

Ans: False

88 A nibble is a group of 16 bits.

Ans: False

89 When a word is to be written in an associative memory, address has got to be given.

Ans: False

90 When two equal numbers are subtracted, the result would be and not___.

Ans: +ZERO, -ZERO.

91 A ___________development system and an ______are essential tools for writing large assembly language programs.
Ans: Microprocessor, assembler

92 In an operation performed by the ALU, carry bit is set to 1 if the end carry C 8 is . It is cleared to 0 (zero) if the carry is _.
Ans: One, zero

93 A successive A/D converter is
(A) a high-speed converter.
(B) a low speed converter.
(C) a medium speed converter.
(D) none of these.

Ans: C

94 When necessary, the results are transferred from the CPU to main memory by
(A) I/O devices.
(B) CPU.
(C) shift registers.
(D) none of these.

Ans: C

96 A combinational logic circuit which sends data coming from a single source to two or more separate destinations is
(A) Decoder.
(B) Encoder.
(C) Multiplexer.
(D) Demultiplexer.

Ans: D

97 In which addressing mode the operand is given explicitly in the instruction

(A) Absolute.
(B) Immediate .
(C) Indirect.
(D) Direct.

Ans: B

98 A stack organized computer has

Ans: D

99 A Program Counter contains a number 825 and address part of the instruction contains the number 24. The effective address in the relative address mode, when an instruction is read from the memory is
(A) 849.
(B) 850.
(C) 801.
(D) 802.

Ans: B

102 A page fault
(A) Occurs when there is an error in a specific page.
(B) Occurs when a program accesses a page of main memory.
(C) Occurs when a program accesses a page not currently in main memory.
(D) Occurs when a program accesses a page belonging to another program.

Ans: C

The load instruction is mostly used to designate a transfer from memory to a processor register known as____.

A. Accumulator
B. Instruction Register
C. Program counter
Ans: A

A group of bits that tell the computer to perform a specific operation is known as____.

A. Instruction code
B. Micro-operation
C. Accumulator
D. Register
Ans: A

The time interval between adjacent bits is called the_____.
A. Word-time B. Bit-time
C. Turn around time
D. Slice time
Ans: B

A k-bit field can specify any one of_____.
A. 3k registers
B. 2k registers
C. K2 registers
D. K3 registers
Ans: B
MIMD stands for . A. Multiple instruction multiple data B. Multiple instruction memory data C. Memory instruction multiple data D. Multiple information memory data Ans: A Logic gates with a set of input and outputs is arrangement of_____.
A. Computational circuit
B. Logic circuit
C. Design circuits
D. Register
Ans: A

The average time required to reach a storage location in memory and obtain its contents is called_____.
A. Latency time.
B. Access time.
C. Turnaround time.
D. Response time.
Ans: B

The BSA instruction is______.
A. Branch and store accumulator
B. Branch and save return address
D. Branch and show accumulator
Ans: B

Computer Organization and Architecture mcq questions
A floating point number that has a O in the MSB of mantissa is said to have_____.
A. Overflow
B. Underflow
C. Important number
D. Undefined
Ans: B

Translation from symbolic program into Binary is done in_____.
A. Two passes.
B. Directly
C. Three passes.
D. Four passes.
Ans: A

The instruction ‘ORG O’ is a______.
A. Machine Instruction.
B. Pseudo instruction.
C. High level instruction.
D. Memory instruction.
Ans: B

‘Aging registers’ are _.
A. Counters which indicate how long ago their associated pages have been
referenced.
B. Registers which keep track of when the program was last accessed.
C. Counters to keep track of last accessed instruction.
D. Counters to keep track of the latest data structures referred.
Ans: A

Memory unit accessed by content is called______.
B. Programmable Memory
C. Virtual Memory
D. Associative Memory
Ans: D

_ register keeps tracks of the instructions stored in program stored in memory.
B. XR (Index Register)
C. PC (Program Counter)
D. AC (Accumulator)
Ans: C

n bits in operation code imply that there are _ possible distinct operators.
A. 2n
B. 2n
C. n/2
D. n2
Ans: B

A three input NOR gate gives logic high output only when_____.
A. one input is high
B. one input is low
C. two input are low
D. all input are high
Ans: D

The circuit converting binary data in to decimal is_____.
A. Encoder
B. Multiplexer
C. Decoder
D.Code converter
Ans: D

The multiplicand register & multiplier register of a hardware circuit implementing booth’s algorithm have (11101) & (1100). The result shall be _. A. (812)10 B. (-12)10 C. (12)10 D. (-812)10 Ans: A PSW is saved in stack when there is a .
A. interrupt recognized
B. execution of RST instruction
C. Execution of CALL instruction
D. All of these
Ans: A

In computers, subtraction is carried out generally by____.
A. 1’s complement method
B. 2’s complement method
C. signed magnitude method
D. BCD subtraction method
Ans: B

The main memory in a Personal Computer (PC) is made of_____.
A. cache memory.
B. static RAM

C. Dynamic Ram
D. bothA.and (B).
Ans: D

Cache memory works on the principle of_____.
A. Locality of data
B. Locality of memory
C. Locality of reference
D. Locality of reference & memory
Ans: C

An n-bit microprocessor has_____.
A. n-bit program counter
C. n-bit ALU
D. n-bit instruction register
Ans: D

When CPU is executing a Program that is part of the Operating System, it is said to be in _.
A. Interrupt mode
B. System mode
C. Half mode
D. Simplex mode
Ans: B

Logic X-OR operation of (4ACO)H& (B53F)H results _.
A. AACB B. 0000

C. FFFF D. ABCD

Ans: C
If the main memory is of 8K bytes and the cache memory is of 2K words. It uses associative mapping. Then each word of cache memory shall be_____.
A. 11 bits
B. 21 bits
C. 16 bits
D. 20 bits
Ans: C

A Stack-organised Computer uses instruction of _.
Ans: C

In a program using subroutine call instruction, it is necessary______.
A. initialize program counter
B. Clear the accumulator
C. Reset the microprocessor
D. Clear the instruction register
Ans: D

Computer Organization and Architecture mcq
Virtual memory consists of _.
A. Static RAM
B. Dynamic RAM
C. Magnetic memory
D. None of these
Ans: A

In signed-magnitude binary division, if the dividend is (11100)2 and divisor is (10011)2 then the result is __.
A. (00100)2
B. (10100)2
C. (11001)2
D. (01100)2
Ans: B

Generally Dynamic RAM is used as main memory in a computer system as it______.
A. Consumes less power
B. has higher speed
C. has lower cell density
D. needs refreshing circuitry
Ans: B

Write Through technique is used in which memory for updating the data _.
A. Virtual memory
B. Main memory
C. Auxiliary memory
D. Cache memory
Ans: D

Cache memory acts between_______.
A. CPU and RAM
B. RAM and ROM
C. CPU and Hard Disk
D. None of these
Ans: A

The circuit used to store one bit of data is known as __.
A. Encoder
B. OR gate
C. Flip Flop
D. Decoder
Ans: C

Von Neumann architecture is __.
A. SISD
B. SIMD
C. MIMD
D. MISD
Ans: A

In a vectored interrupt.
A. the branch address is assigned to a fixed location in memory.
B. the interrupting source supplies the branch information to the processor through
an interrupt vector.
C. the branch address is obtained from a register in the processor
D. none of the above
Ans: B

. In a memory-mapped I/O system, which of the following will not be there?
A. LDA
B. IN
D. OUT
Ans: A

If memory access takes 20 ns with cache and 110 ns without it, then the ratio (cache uses a 10 ns memory) is _.
A. 93%
B. 90%
C. 88%
D. 87%
Ans: B

The addressing mode used in an instruction of the form ADD X Y, is _.
A. Absolute
B. indirect
C. index
D. none of these
Ans: C

_ register keeps track of the instructions stored in program stored in memory.
B. XR (Index Register)
C. PC (Program Counter)
D. AC (Accumulator)
Ans: C

The idea of cache memory is based __.
A. on the property of locality of reference
B. on the heuristic 90-10 rule
C. on the fact that references generally tend to cluster
D. all of the above
Ans: A

Which of the following is not a weighted code?
A. Decimal Number system
B. Excess 3-cod
C. Binary number System
D. None of these
Ans: B

The average time required to reach a storage location in memory and obtain its contents is called the _.
A. seek time
B. turnaround time
C. access time
D. transfer time
Ans: C

(2FAOC)16 is equivalent to _.
A. (195 084)10
B. (001011111010 0000 1100)2
C. Both A.and (B)
D. None of these
Ans: B

The circuit used to store one bit of data is known as_______.
A. Register
B. Encoder
C. Decoder
D. Flip Flop
Ans: D

. Computers use addressing mode techniques for __.
A. giving programming versatility to the user by providing facilities as pointers to
memory counters for loop control
B. to reduce no. of bits in the field of instruction
C. specifying rules for modifying or interpreting address field of the instruction
D. All the above
Ans: D

What characteristic of RAM memory makes it not suitable for permanent storage?
A. too slow
B. unreliable
C. it is volatile
D. too bulky
Ans: C

The amount of time required to read a block of data from a disk into memory is composed of seek time, rotational latency, and transfer time. Rotational latency refers to __.
A. the time its takes for the platter to make a full rotation
B. the time it takes for the read-write head to move into position over the
appropriate track
C. the time it takes for the platter to rotate the correct sector under the head
D. none of the above
Ans: A

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Basic of Digital Image Processing

ALL unite digital Image Processing MCQ

#### HPC MCQ UNIT – 5 AKTU MCQ

AKTU MCQ

AKTU MCQ

AKTU MCQ

AKTU MCQ