OCR J277 Computer Science Paper 1 Revision Test 1

What is the primary function of the Arithmetic Logic Unit (ALU) in a CPU?

• Controls the flow of data in and out of the CPU

• Temporarily holds small amounts of data

• Performs calculations and logical operations

• Stores regularly used data for quick access

Answer explanation

The primary function of the Arithmetic Logic Unit (ALU) in a CPU is to perform calculations and logical operations.

Amelia is configuring her new workstation for advanced video editing tasks. Which component of her computer system is crucial for processing all data and instructions?

• Control Unit

• Arithmetic Logic Unit

• Central Processing Unit

• Cache

Answer explanation

The Central Processing Unit (CPU) is crucial for processing all data and instructions in a computer system, making it essential for advanced video editing tasks.

What is the role of the Control Unit (CU) within the CPU?

• Performs calculations including addition and subtraction

• Temporarily holds small amounts of data

• Controls the flow of data and manages instruction execution

• Stores regularly used data for quick access

Answer explanation

The role of the Control Unit (CU) within the CPU is to control the flow of data and manage instruction execution.

Isabelle is building a custom PC for gaming. Which factor does NOT affect the CPU performance of her gaming setup?

• Number of cores

• Clock speed

• Cache size

• Type of peripherals connected

Answer explanation

The correct choice is the 'Type of peripherals connected' because it does not affect the CPU performance of a gaming setup, unlike the number of cores, clock speed, and cache size.

What is the role of the Memory Address Register (MAR) in a CPU?

• It stores the data being transferred to and from the memory unit

• It holds the address of the next instruction to be executed

• It contains the address of the memory location currently being accessed

• It decodes the instructions fetched from memory

Answer explanation

It contains the address of the memory location currently being accessed

Which component of the CPU holds the actual data or instruction that has been fetched from memory or is waiting to be written to memory?

• Arithmetic Logic Unit (ALU)

• Memory Address Register (MAR)

• Memory Data Register (MDR)

• Control Unit

Answer explanation

The Memory Data Register (MDR) component of the CPU holds the actual data or instruction that has been fetched from memory or is waiting to be written to memory.

What is the primary function of the Program Counter (PC) in the Fetch-Execute Cycle?

• It stores the data needed for CPU operations.

• It keeps track of the next instruction to execute.

• It manages the input/output operations of the system.

• It performs arithmetic and logical operations on data.

Answer explanation

It keeps track of the next instruction to execute.

In the Fetch-Execute Cycle, what happens during the "Decode" step?

• The instruction in the MDR is decoded by the control unit.

• The program counter is incremented to point to the next instruction.

• Data is written to memory.

• The memory address is copied from the program counter to the MAR.

Answer explanation

In the Fetch-Execute Cycle, during the 'Decode' step, the instruction in the MDR is decoded by the control unit.

Which type of memory loses its data when the power is turned off?

• Hard Drive

• RAM

• SSD

• ROM

Answer explanation

RAM is the type of memory that loses its data when the power is turned off, making it volatile in nature.

Muhammad is working on his computer to complete a project. He needs to access data quickly while he works. Which type of memory is known as the main temporary memory in a computer that allows Muhammad to access this data quickly?

• ROM

• RAM

• Virtual Memory

• Secondary Storage

Answer explanation

RAM is the main temporary memory in a computer that allows quick access to data, making it ideal for Muhammad's project work.