170+ Computer System Architecture Solved MCQs

1.

In Reverse Polish notation, expression A*B+C*D is written as

A. ab*cd*+
B. a*bcd*+
C. ab*cd+*
D. a*b*cd+
Answer» A. ab*cd*+
2.

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.
Answer» C. includes many processing units under the supervision of a common control unit
3.

Floating point representation is used to store

A. boolean values
B. whole numbers
C. real integers
D. integers
Answer» C. real integers
4.

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
Answer» D. 2 megabytes/sec
5.

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
Answer» A. uses alphabetic codes in place of binary numbers used in machine language
6.

In computers, subtraction is generally carried out by

A. 9’s complement
B. 10’s complement
C. 1’s complement
D. 2’s complement
Answer» D. 2’s complement
7.

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
Answer» A. the time its takes for the platter to make a full rotation
8.

What characteristic of RAM memory makes it not suitable for permanent storage?

A. too slow
B. unreliable
C. it is volatile
D. too bulky
Answer» C. it is volatile
9.

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
Answer» D. all the above
10.

The circuit used to store one bit of data is known as

A. register
B. encoder
C. decoder
D. flip flop
Answer» D. flip flop
11.

(2FAOC) 16 is equivalent to

A. (195 084) 10
B. (001011111010 0000 1100) 2
C. both (a) and (b)
D. none of these
Answer» B. (001011111010 0000 1100) 2
12.

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
Answer» C. access time
13.

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
Answer» B. excess 3-cod
14.

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
Answer» A. on the property of locality of reference
15.

The addressing mode used in an instruction of the form ADD X Y, is

A. absolute
B. indirect
C. index
D. none of these
Answer» C. index
16.

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%
Answer» B. 90%
17.

In a memory-mapped I/O system, which of the following will not be there?

A. lda
B. in
C. add
D. out
Answer» A. lda
18.

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
Answer» B. the interrupting source supplies the branch information to the processor through an interrupt vector.
19.

Von Neumann architecture is

A. sisd
B. simd
C. mimd
D. misd
Answer» A. sisd
20.

The circuit used to store one bit of data is known as

A. encoder
B. or gate
C. flip flop
D. decoder
Answer» C. flip flop
21.

Cache memory acts between

A. cpu and ram
B. ram and rom
C. cpu and hard disk
D. none of these
Answer» A. cpu and ram
22.

Write Through technique is used in which memory for updating the data

A. virtual memory
B. main memory
C. auxiliary memory
D. cache memory
Answer» D. cache memory
23.

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
Answer» B. has higher speed
24.

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
Answer» B. (10100) 2
25.

Virtual memory consists of

A. static ram
B. dynamic ram
C. magnetic memory
D. none of these
Answer» A. static ram
26.

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
Answer» D. clear the instruction register
27.

A Stack-organised Computer uses instruction of

A. indirect addressing
B. two-addressing
C. zero addressing
D. index addressing
Answer» C. zero addressing
28.

Then each word of cache memory shall be

A. 11 bits
B. 21 bits
C. 16 bits
D. 20 bits
Answer» C. 16 bits
29.

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 =?
Answer» D. n tqd =?
30.

Logic X-OR operation of (4ACO) H & (B53F) H results

A. aacb
B. 0000
C. ffff
D. abcd
Answer» C. ffff
31.

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
Answer» B. system mode
32.

An n-bit microprocessor has

A. n-bit program counter
B. n-bit address register
C. n-bit alu
D. n-bit instruction register
Answer» D. n-bit instruction register
33.

Cache memory works on the principle of

A. locality of data
B. locality of memory
C. locality of reference
D. locality of reference & memory
Answer» C. locality of reference
34.

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) .
Answer» D. both (a) and (b) .
35.

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
Answer» B. 2’s complement method
36.

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
Answer» A. interrupt recognised
37.

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
Answer» A. (812) 10
38.

The circuit converting binary data in to decimal is

A. encoder
B. multiplexer
C. decoder
D. code converter
Answer» D. code converter
39.

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
Answer» D. all input are high
40.

n bits in operation code imply that there are ___________ possible distinct operators

A. 2n
B. 2n
C. n/2
D. n2
Answer» B. 2n
41.

_________ register keeps tracks of the instructions stored in program stored in memory.

A. ar (address register)
B. xr (index register)
C. pc (program counter)
D. ac (accumulator)
Answer» C. pc (program counter)
42.

Memory unit accessed by content is called

A. read only memory
B. programmable memory
C. virtual memory
D. associative memory
Answer» D. associative memory
43.

‘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.
Answer» A. counters which indicate how long ago their associated pages have been referenced.
44.

The instruction ‘ORG O’ is a

A. machine instruction.
B. pseudo instruction.
C. high level instruction.
D. memory instruction.
Answer» B. pseudo instruction.
45.

Translation from symbolic program into Binary is done in

A. two passes.
B. directly
C. three passes.
D. four passes.
Answer» A. two passes.
46.

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
Answer» B. underflow
47.

The BSA instruction is

A. branch and store accumulator
B. branch and save return address
C. branch and shift address
D. branch and show accumulator
Answer» B. branch and save return address
48.

Logic gates with a set of input and outputs is arrangement of

A. combinational circuit
B. logic circuit
C. design circuits
D. register
Answer» A. combinational circuit
49.

MIMD stands for

A. multiple instruction multiple data
B. multiple instruction memory data
C. memory instruction multiple data
D. multiple information memory data
Answer» A. multiple instruction multiple data
50.

A k-bit field can specify any one of

A. 3k registers
B. 2k registers
C. k2 registers
D. k3 registers
Answer» B. 2k registers
51.

The time interval between adjacent bits is called the

A. word-time
B. bit-time
C. turn around time
D. slice time
Answer» B. bit-time
52.

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
Answer» A. instruction code
53.

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
D. memory address register
Answer» A. accumulator
54.

The communication between the components in a microcomputer takes place via the address and

A. i/o bus
B. data bus
C. address bus
D. control lines
Answer» B. data bus
55.

An instruction pipeline can be implemented by means of

A. lifo buffer
B. fifo buffer
C. stack
D. none of the above
Answer» B. fifo buffer
56.

Data input command is just the opposite of a

A. test command
B. control command
C. data output
D. data channel
Answer» C. data output
57.

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.
Answer» A. generates the address of next micro instruction to be executed.
58.

. A binary digit is called a

A. bit
B. byte
C. number
D. character
Answer» A. bit
59.

A flip-flop is a binary cell capable of storing information of

A. one bit
B. byte
C. zero bit
D. eight bit
Answer» A. one bit
60.

The operation executed on data stored in registers is called

A. macro-operation
B. micro-operation
C. bit-operation
D. byte-operation
Answer» B. micro-operation
61.

MRI indicates

A. memory reference information.
B. memory reference instruction.
C. memory registers instruction.
D. memory register information
Answer» B. memory reference instruction.
62.

Self-contained sequence of instructions that performs a given computational task is called

A. function
B. procedure
C. subroutine
D. routine
Answer» A. function
63.

Microinstructions are stored in control memory groups, with each group specifying a

A. routine
B. subroutine
C. vector
D. address
Answer» A. routine
64.

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
Answer» A. i/o interface
65.

Status bit is also called

A. binary bit
B. flag bit
C. signed bit
D. unsigned bit
Answer» B. flag bit
66.

An address in main memory is called

A. physical address
B. logical address
C. memory address
D. word address
Answer» A. physical address
67.

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.
Answer» B. direct.
68.

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
Answer» A. 111011 & 100100
69.

in the external main memory are called

A. data transfer instructions.
B. program control instructions.
C. input-output instructions.
D. logical instructions.
Answer» A. data transfer instructions.
70.

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.
Answer» D. counter.
71.

The performance of cache memory is frequently measured in terms of a quantity called

A. miss ratio.
B. hit ratio.
C. latency ratio.
D. read ratio.
Answer» C. latency ratio.
72.

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.
Answer» B. state diagram.
73.

Content of the program counter is added to the address part of the instruction in order to obtain the effective address is called.

A. relative address mode.
B. index addressing mode.
C. register mode.
D. implied mode.
Answer» A. relative address mode.
74.

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.
Answer» D. dma.
75.

The 2s compliment form (Use 6 bit word) of the number 1010 is

A. 111100.
B. 110110.
C. 110111.
D. 1011.
Answer» B. 110110.
76.

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.
Answer» C. shift register.
77.

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.
Answer» C. address of the top element of the stack
78.

Which of the following interrupt is non maskable

A. intr.
B. rst 7.5.
C. rst 6.5.
D. trap.
Answer» D. trap.
79.

Which of the following is a main memory

A. secondary memory.
B. auxiliary memory.
C. cache memory.
D. virtual memory.
Answer» C. cache memory.
80.

Which of the following are not a machine instructions

A. mov.
B. org.
C. end.
D. (b) & (c) .
Answer» D. (b) & (c) .
81.

In Assembly language programming, minimum number of operands required for an instruction is/are

A. zero.
B. one.
C. two.
D. both (b) & (c) .
Answer» A. zero.
82.

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.
Answer» B. 4 gb.
83.

The memory unit that communicates directly with the CPU is called the

A. main memory
B. secondary memory
C. shared memory
D. auxiliary memory.
Answer» A. main memory
84.

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.
Answer» B. access time.
85.

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.
Answer» C. a medium speed converter.
86.

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.
Answer» C. shift registers.
87.

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.
Answer» D. demultiplexer.
88.

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

A. absolute.
B. immediate .
C. indirect.
D. direct.
Answer» B. immediate .
89.

A stack organized computer has

A. three-address instruction.
B. two-address instruction.
C. one-address instruction.
D. zero-address instruction.
Answer» D. zero-address instruction.
90.

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.
Answer» B. 850.
91.

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.
Answer» C. occurs when a program accesses a page not currently in main memory.
92.

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
D. . memory address register
Answer» A. . accumulator
93.

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
Answer» A. . instruction code
94.

The time interval between adjacent bits is called the_____.

A. . word-time
B. . bit-time
C. . turn around time
D. . slice time
Answer» B. . bit-time
95.

A k-bit field can specify any one of_____.

A. . 3k registers
B. . 2k registers
C. . k2 registers
D. . k3 registers
Answer» B. . 2k registers
96.

MIMD stands for _____.

A. . multiple instruction multiple data
B. . multiple instruction memory data
C. . memory instruction multiple data
D. . multiple information memory data
Answer» A. . multiple instruction multiple data
97.

Logic gates with a set of input and outputs is arrangement of______.

A. . computational circuit
B. . logic circuit
C. . design circuits
D. . register
Answer» A. . computational circuit
98.

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.
Answer» B. . access time.
99.

The BSA instruction is______.

A. . branch and store accumulator
B. . branch and save return address
C. . branch and shift address
D. . branch and show accumulator
Answer» B. . branch and save return address
100.

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
Answer» B. . underflow
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