CPU Instruction Execution and Bitwise Operations MCQs
Q#1: How does the CPU fetch an instruction from memory?
(A) By directly executing the instruction
(B) By decoding the instruction
(C) By obeying the instruction
(D) By transferring it using a bus
Answer: (D) By transferring it using a bus
Q#2: What determines the order of execution for instructions in memory?
(A) The CPU’s program counter
(B) The CPU’s instruction register
(C) The CPU’s control unit
(D) The CPU’s arithmetic/logic unit
Answer: (A) The CPU’s program counter
Q#3: What is the role of the Instruction Register?
(A) To execute instructions
(B) To decode instructions
(C) To hold the currently executed instruction
(D) To fetch instructions from memory
Answer: (C) To hold the currently executed instruction
Q#4: How are instructions executed in the CPU?
(A) Instructions are fetched from memory
(B) Instructions are decoded
(C) Instructions are executed
(D) Instructions are stored in the program counter
Answer: (C) Instructions are executed
Q#5: In Figure 45, what type of program is being executed?
(A) Data manipulation program
(B) Memory reading program
(C) Addition program
(D) Memory storing program
Answer: (C) Addition program
Q#6: What does the CPU do after analyzing the instruction in its instruction register during the execution step?
(A) It fetches the next instruction
(B) It decodes the instruction
(C) It stores the instruction in memory
(D) It increments the program counter
Answer: (A) It fetches the next instruction
Q#7: Which hexadecimal value is obtained in the example?
(A) A4
(B) 166D
(C) A6
(D) 5056
Answer: (C) A6
Q#8: Which register holds the result of the two’s complement addition in the CPU?
(A) Program Counter
(B) Instruction Register
(C) Arithmetic/Logic Unit
(D) Register 0
Answer: (D) Register 0
Q#9: What is the final instruction in the program?
(A) A4
(B) A6
(C) C000
(D) 306E
Answer: (C) C000
Q#10: In data manipulation, what is one major use of the AND operation?
(A) Combining two strings of bits
(B) Duplicating a bit pattern
(C) Inverting all the bits
(D) Moving bits within a register
Answer: (B) Duplicating a bit pattern
Q#11: When using the AND operation for masking, what does the mask determine?
(A) The position of the result
(B) The type of operation to perform
(C) Which part of the other operand affects the result
(D) The color of the result
Answer: (C) Which part of the other operand affects the result
Q#12: What does the OR operation do when used with a mask?
(A) Duplicates a part of a string
(B) Inverts all the bits in a string
(C) Rotates the bits in a string
(D) Discards the bits in a string
Answer: (A) Duplicates a part of a string
Q#13: How is the XOR operation often used?
(A) To perform multiplication
(B) To perform division
(C) To form the complement of a bit string
(D) To perform circular shifts
Answer: (C) To form the complement of a bit string
Q#14: What are the operations in the class of rotation and shift operations used for?
(A) Solving alignment problems
(B) Multiplying two’s complement representations
(C) Adding two bit patterns
(D) Inverting all the bits in a register
Answer: (A) Solving alignment problems
Q#15: What distinguishes a circular shift from a logical shift?
(A) The direction of motion
(B) The circular shift always fills the hole with 1
(C) The logical shift always fills the hole with 0
(D) The circular shift never discards bits
Answer: (B) The circular shift always fills the hole with 1
Q#16: How can subtraction be simulated using addition in 2’s complement notation?
(A) By adding the binary of the first number to the binary of the second number
(B) By adding the binary of the first number to the negation of the second number
(C) By adding the binary of the second number to the binary of the first number
(D) By multiplying the binary of the first number with the binary of the second number
Answer: (B) By adding the binary of the first number to the negation of the second number
Q#17: What is multiplication in the context of arithmetic operators?
(A) Repetitive subtraction
(B) Repetitive addition
(C) Division by addition
(D) Division by subtraction
Answer: (B) Repetitive addition
Q#18: How can division be achieved using some small CPUs?
(A) By adding
(B) By subtracting
(C) By multiplication
(D) By division
Answer: (B) By subtracting
Q#19: What is the straightforward method of handling numbers stored in 2’s complement notation?
(A) Multiplication
(B) Division
(C) Addition
(D) Subtraction
Answer: (C) Addition
Q#20: In the context of handling numbers stored in floating-point notation, what needs to be considered?
(A) The number of bits in the register
(B) The position of the sign bit
(C) The color representation of the numbers
(D) The type of operation to perform
Answer: (B) The position of the sign bit