ALU Design MCQs

By: Prof. Dr. Fazal Rehman | Last updated: September 20, 2024

Which of the following components is part of the Arithmetic Logic Unit (ALU)? A) Memory B) Control Unit C) Registers D) Adder Answer: D) Adder The primary function of an ALU is to perform __________. A) Memory management B) Logical and arithmetic operations C) Instruction fetching D) Data storage Answer: B) Logical and arithmetic operations What does the ALU use to carry out arithmetic operations like addition and subtraction? A) Control signals B) Flip-flops C) Accumulators D) Adders and subtractors Answer: D) Adders and subtractors In a computer, the ALU is part of the __________. A) Central Processing Unit (CPU) B) Memory Unit C) Input/Output System D) Secondary Storage Answer: A) Central Processing Unit (CPU) Which operation is not performed by the ALU? A) Addition B) Subtraction C) Program Counter update D) Bitwise AND Answer: C) Program Counter update Which of the following logic operations is performed by an ALU? A) OR operation B) NAND operation C) NOR operation D) All of the above Answer: D) All of the above The ALU design includes a collection of __________. A) Registers and memory B) Multiplexers and logic gates C) Control units D) Instruction decoders Answer: B) Multiplexers and logic gates Which of the following is a common input to an ALU? A) Program counter B) Status register C) Data and instruction D) Control signals Answer: C) Data and instruction What does the ‘L’ in ALU stand for? A) Large B) Logic C) Loop D) Load Answer: B) Logic ALU outputs are directly connected to __________. A) Accumulators B) Registers C) Program Counter D) Control Unit Answer: B) Registers The control unit interacts with the ALU to perform __________. A) Memory read/write B) Arithmetic and logic operations C) I/O operations D) Interrupt handling Answer: B) Arithmetic and logic operations Which of the following arithmetic operations cannot be performed by a basic ALU? A) Addition B) Division C) Subtraction D) Multiplication Answer: B) Division How does an ALU perform a subtraction operation? A) Using only an adder B) By inverting the bits and adding C) Using a subtractor D) Using a multiplier Answer: B) By inverting the bits and adding ALU flags are used to indicate __________. A) Execution speed B) The result of an operation C) Instruction types D) Cache state Answer: B) The result of an operation Which flag in the ALU indicates that an arithmetic operation has generated a carry? A) Zero flag B) Carry flag C) Overflow flag D) Sign flag Answer: B) Carry flag The Zero Flag in an ALU is set when __________. A) The result of an operation is non-zero B) The result of an operation is zero C) There is an overflow D) A carry is generated Answer: B) The result of an operation is zero The ALU works in conjunction with the __________ to execute instructions. A) Instruction Set Architecture (ISA) B) Memory Management Unit (MMU) C) Control Unit (CU) D) Input/Output Unit (I/O) Answer: C) Control Unit (CU) What is the role of multiplexers in an ALU? A) To select between different operations B) To store intermediate results C) To handle data input/output D) To control memory access Answer: A) To select between different operations Which of the following is an example of a logical operation in an ALU? A) Addition B) Multiplication C) OR D) Division Answer: C) OR The Overflow Flag in an ALU is used to detect __________. A) Zero result B) Signed overflow C) Unsigned carry D) Even result Answer: B) Signed overflow The ALU’s shift operation is used to __________. A) Shift data left or right B) Add two numbers C) Multiply numbers D) Invert data bits Answer: A) Shift data left or right What is the primary role of the Accumulator in ALU operations? A) Store results temporarily B) Control instruction flow C) Address memory locations D) Decode instructions Answer: A) Store results temporarily Which part of the CPU fetches data for the ALU to process? A) Memory B) Control Unit C) Cache D) Registers Answer: B) Control Unit How is a multiplication operation typically performed in ALU design? A) By repeatedly adding B) Using a direct multiplier circuit C) By repeatedly subtracting D) Using division logic Answer: A) By repeatedly adding Which component signals the ALU on what operation to perform? A) Status Register B) Control Unit C) Memory D) Instruction Pointer Answer: B) Control Unit Which operation would cause the Carry Flag in an ALU to be set? A) Subtraction without carry B) Addition causing overflow C) Logical AND D) Multiplication by zero Answer: B) Addition causing overflow ALUs in modern processors can perform both integer and __________ arithmetic. A) Floating-point B) String-based C) Symbolic D) Character-based Answer: A) Floating-point In many ALU designs, which of the following operations can be performed using a left-shift operation? A) Subtraction B) Division by 2 C) Multiplication by 2 D) Addition of two numbers Answer: C) Multiplication by 2 Which of the following units is responsible for handling conditional branches based on ALU operations? A) Memory Unit B) Instruction Fetch Unit C) Control Unit D) ALU Flags Answer: C) Control Unit Which of the following statements is true about the relationship between the ALU and the CPU? A) The CPU controls the ALU B) The ALU stores the instructions for the CPU C) The ALU manages the I/O operations D) The ALU is independent of the CPU Answer: A) The CPU controls the ALU Which of the following is a secondary function of the ALU? A) Instruction decoding B) Data comparison C) Memory allocation D) I/O processing Answer: B) Data comparison The Sign Flag in an ALU is set when __________. A) The result is negative B) The result is zero C) A carry is generated D) An overflow occurs Answer: A) The result is negative What component in the CPU typically provides operands for the ALU? A) Cache B) Register file C) Hard drive D) Control bus Answer: B) Register file Logical operations in an ALU generally involve __________. A) Addition and subtraction B) Multiplication and division C) Bitwise operations D) Floating-point arithmetic Answer: C) Bitwise operations Which of the following best describes an ALU in modern microprocessors? A) A separate processing chip B) A fixed-function hardware component C) A programmable unit D) A multi-core processing unit Answer: B) A fixed-function hardware component The ALU in a CPU performs shifts and rotates for __________. A) Arithmetic only B) Logical only C) Both arithmetic and logical purposes D) Memory purposes Answer: C) Both arithmetic and logical purposes Which of the following best describes the function of a half-adder in an ALU? A) Performs logical XOR operations B) Adds two binary digits without considering carry-in C) Performs subtraction D) Multiplies two binary numbers Answer: B) Adds two binary digits without considering carry-in A carry-lookahead adder improves ALU performance by __________. A) Increasing the bit size B) Reducing propagation delay C) Storing intermediate values D) Reducing memory access time Answer: B) Reducing propagation delay What is the role of a Barrel Shifter in some ALUs? A) Multiplies two numbers quickly B) Divides numbers by powers of 2 C) Shifts multiple bits simultaneously D) Manages memory addressing Answer: C) Shifts multiple bits simultaneously In ALU design, a ripple carry adder is slower than a carry-lookahead adder because __________. A) It requires more power B) It propagates carry through each bit C) It has more gates D) It uses floating-point arithmetic Answer: B) It propagates carry through each bit Which logic gate is essential in the design of an ALU’s adder circuit? A) AND gate B) OR gate C) XOR gate D) NOR gate Answer: C) XOR gate What is the purpose of using multiplexers in ALU design? A) To reduce circuit complexity B) To select between different operations C) To handle overflow detection D) To store results Answer: B) To select between different operations Which type of arithmetic operations can be performed by the ALU without any additional components? A) Integer division B) Subtraction C) Floating-point multiplication D) Exponentiation Answer: B) Subtraction What is a combinational logic circuit used in the ALU for performing addition? A) Full Adder B) Latch C) Multiplexer D) Flip-flop Answer: A) Full Adder

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• Introduction to Computer Architecture MCQs
  • Evolution of Computer Architecture MCQs
  • von Neumann vs Harvard Architecture MCQs
• Basic Components of a Computer System MCQs
  • Central Processing Unit (CPU) MCQs
  • Memory (RAM, ROM, Cache) MCQs
  • Input/Output (I/O) Devices MCQs
  • Buses (Data, Address, Control) MCQs
• CPU Organization MCQs
  • ALU (Arithmetic Logic Unit) MCQs
  • Control Unit MCQs
  • Registers (General Purpose, Special Purpose) MCQs
  • Flags and Status Registers MCQs
• Instruction Set Architecture (ISA) MCQs
  • Types of Instructions (Data Movement, Arithmetic, Control) MCQs
  • Addressing Modes (Immediate, Direct, Indirect, Indexed) MCQs
  • Instruction Formats MCQs
  • RISC (Reduced Instruction Set Computer) vs CISC (Complex Instruction Set Computer) MCQs
• Microarchitecture MCQs
  • Pipelining (Stages and Hazards) MCQs
  • Superscalar Architecture MCQs
  • Multithreading MCQs
  • Out-of-Order Execution MCQs
• Memory Hierarchy MCQs
  • Cache Memory (L1, L2, L3) MCQs
  • Virtual Memory MCQs
  • Paging and Segmentation MCQs
  • TLB (Translation Lookaside Buffer) MCQs
• Cache Memory MCQs
  • Cache Mapping Techniques (Direct, Associative, Set-Associative) MCQs
  • Cache Coherency MCQs
  • Write Policies (Write-Through, Write-Back) MCQs
  • Cache Miss and Hit MCQs
• Input/Output Organization MCQs
  • I/O Techniques (Polling, Interrupts, DMA) MCQs
  • I/O Mapping (Memory-Mapped I/O, Isolated I/O) MCQs
  • Interrupt Handling MCQs
• Bus Architecture MCQs
  • System Bus (Data, Address, Control) MCQs
  • Bus Arbitration MCQs
  • Synchronous vs Asynchronous Buses MCQs
• Performance Metrics MCQs
  • Clock Speed and Cycles per Instruction (CPI) MCQs
  • MIPS (Million Instructions per Second) MCQs
  • FLOPS (Floating-Point Operations per Second) MCQs
  • Amdahl’s Law MCQs
• Parallelism in Computer Architecture MCQs
  • Instruction-Level Parallelism (ILP) MCQs
  • Data-Level Parallelism (DLP) MCQs
  • Thread-Level Parallelism (TLP) MCQs
  • Symmetric Multiprocessing (SMP) vs Asymmetric Multiprocessing (AMP) MCQs
• Multicore and Multiprocessor Systems MCQs
  • Multicore Architectures MCQs
  • Shared Memory vs Distributed Memory MCQs
  • Interconnection Networks MCQs
• Control Unit Design MCQs
  • Hardwired Control vs Microprogrammed Control MCQs
  • Control Signals and Timing MCQs
  • Instruction Cycle and Control Flow MCQs
• Pipeline Hazards MCQs
  • Structural, Data, and Control Hazards MCQs
  • Techniques to Overcome Hazards (Stalling, Forwarding, Branch Prediction) MCQs
• Branch Prediction and Speculation MCQs
  • Static and Dynamic Branch Prediction MCQs
  • Speculative Execution MCQs
  • Branch Target Buffers MCQs
• Arithmetic and Logic Operations MCQs
  • Integer and Floating-Point Arithmetic MCQs
  • ALU Design MCQs
  • Fixed-Point vs Floating-Point Representation MCQs
• Memory Management MCQs
  • Paging, Segmentation, and Virtual Memory MCQs
  • Memory Protection and Privilege Levels MCQs
  • Memory Allocation and Deallocation MCQs
• Power and Energy Efficiency MCQs
  • Power Dissipation in CPUs MCQs
  • Low-Power Design Techniques MCQs
  • Energy-Aware Computing MCQs
• Advanced Topics MCQs
  • GPU Architecture and Usage MCQs
  • Quantum Computing Basics MCQs
  • Neuromorphic Computing MCQs
• Emerging Trends
  • Cloud Computing Architectures MCQs
  • Edge Computing MCQs
  • AI Accelerators MCQs