140+ Computer Organization and Architecture Solved MCQs

101.

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
102.

Translation from symbolic program into Binary is done in_____.

A. Two passes.
B. Directly
C. Three passes.
D. Four passes.
Answer» A. Two passes.
103.

The instruction ‘ORG O’ is a______.

A. Machine Instruction.
B. Pseudo instruction.
C. High level instruction.
D. Memory instruction.
Answer» B. Pseudo instruction.
104.

‘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.
105.

Memory unit accessed by content is called______.

A. Read only memory
B. Programmable Memory
C. Virtual Memory
D. Associative Memory
Answer» D. Associative Memory
106.

_________ 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)
107.

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

A. 2n
B. 2n
C. n/2
D. n2
Answer» B. 2n
108.

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
109.

The circuit converting binary data in to decimal is_____.

A. Encoder
B. Multiplexer
C. Decoder
D. Code converter
Answer» D. Code converter
110.

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
111.

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
Answer» A. interrupt recognized
112.

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
113.

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

A. cache memory.
B. static RAM
C. Dynamic Ram
D. bothA.and (B).
Answer» D. bothA.and (B).
114.

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
115.

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
116.

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
117.

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

A. AACB
B. 0000
C. FFFF
D. ABCD
Answer» C. FFFF
118.

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
Answer» C. 16 bits
119.

A Stack-organised Computer uses instruction of _____.

A. Indirect addressing
B. Two-addressing
C. Zero addressing
D. Index addressing
Answer» C. Zero addressing
120.

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
Answer» D. Clear the instruction register
121.

Virtual memory consists of _______.

A. Static RAM
B. Dynamic RAM
C. Magnetic memory
D. None of these
Answer» A. Static RAM
122.

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
123.

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
Answer» B. has higher speed
124.

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
125.

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
126.

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
127.

Von Neumann architecture is ______.

A. SISD
B. SIMD
C. MIMD
D. MISD
Answer» A. SISD
128.

. 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
129.

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%
Answer» B. 90%
130.

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
131.

_________ register keeps track 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)
132.

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
133.

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
134.

(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
135.

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
136.

. 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
137.

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
138.

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
139.

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
140.

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
141.

Floating point representation is used to store ______.

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