Computer Fundamentals Questions and Answers – Registers

This set of Computer Fundamentals Multiple Choice Questions & Answers (MCQs) focuses on “Registers”.

1. CPU has built-in ability to execute a particular set of machine instructions, called as __________
a) Instruction Set
b) Registers
c) Sequence Set
d) User instructions
View Answer

Answer: a
Explanation: An instruction is any task which is to be performed by the processor. Instructions are stored in the register. Instruction set is the set of machine instructions.

2. Opcode indicates the operations to be performed.
a) True
b) False
View Answer

Answer: a
Explanation: Every instruction has an opcode. Additionally, it may have one or more operands and the op code indicates the operation to be performed.

3. The length of a register is called _______
a) word limit
b) word size
c) register limit
d) register size
View Answer

Answer: b
Explanation: The length of a register is called word size. It tells the number of bits a register can store.
Registers are a part of the CPU.

4. The _________ holds the contents of the accessed memory word.
a) MAR
b) MBR
c) PC
d) IR
View Answer

Answer: b
Explanation: The MBR holds the contents of the accessed (read/written) memory word.
MBR stands for Memory Buffer Register.

5. Which of the following is not a visible register?
a) General Purpose Registers
b) Address Register
c) Status Register
d) MAR
View Answer

Answer: d
Explanation: MAR or the memory address register is not a visible register. This register is user inaccessible. It contains the address of the memory block to be read or written to.

6. Which of the following is a data transfer instruction?
a) STA 16-bit address
b) ADD A, B
c) MUL C, D
d) RET
View Answer

Answer: a
Explanation: The instruction STA 16-bit address is a data transfer instruction.
STA means Store in Accumulator.

7. What is correct instruction if you want the control to go to the location 2000h?
a) MOV 2000h
b) MOV A, 2000h
c) JMP 2000h
d) RET 2000h
View Answer

Answer: c
Explanation: The JMP instruction is used to move to a particular location. In 8085 microprocessor, JMP statement tells the processor to go to location 2000h (here).

8. What kind of a flag is the sign flag?
a) General Purpose
b) Status
c) Address
d) Instruction
View Answer

Answer: b
Explanation: Sign flag is a type of status register or the flag register. It is used to indicate the sign of certain bits.

9. The number of sign bits in a 32-bit IEEE format __________
a) 1
b) 11
c) 9
d) 23
View Answer

Answer: a
Explanation: There is only 1 sign bit in all the standards. In a 32-bit format, there is 1 sign bit, 8 bits for the exponent and 23 bits for the mantissa.

10. New CPU whose instruction set includes the instruction set of its predecessor CPU is said to be ___________ with its predecessor.
a) fully compatible
b) forward compatible
c) compatible
d) backward compatible
View Answer

Answer: d
Explanation: The CPU is called backward compatible since it contains the instruction set of its predecessor. Manufacturers tend to group their CPUs into families having similar instruction set.

Sanfoundry Global Education & Learning Series – Computer Fundamentals.

To practice all areas of Computer Fundamentals, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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