Lesson T4.2.1

T4.2.1 How instructions are stored and executed Quiz: KS3 Computing, Unit 4

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson T4.2.1, How instructions are stored and executed: 20 multiple choice questions for the KS3 Computing (National Curriculum), Unit 4: Computer systems, written with Revision Ninja.

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The 20 questions

  1. What is meant by the term 'fetch-decode-execute' cycle?

    • The method used to compress a file so it takes up less space on the storage device
    • The process of loading an operating system from the hard drive when the computer starts
    • The sequence of steps used to connect a device to a network for the first time
    • The repeated process a processor uses to fetch an instruction, decode it and carry it out

  2. What is the job of the program counter?

    • It counts how many programs are currently open on the computer at any one time
    • It records how many times a user has clicked a button in the running application
    • It holds the address of the next instruction that the processor is to fetch
    • It stores the total number of files on the hard drive in a list for the user

  3. What is stored in the instruction register?

    • The instruction that has been fetched from memory and is waiting to be decoded
    • The amount of data that has been sent to the output device during this session
    • The result of the most recent calculation performed by the arithmetic logic unit
    • The address of the next instruction that the processor should carry out next

  4. Which part of the processor performs arithmetic and logical operations?

    • The control unit, which sends signals to coordinate the other parts of the processor
    • The arithmetic logic unit
    • The cache memory, which holds copies of the data most recently used by the processor
    • The clock, which sends regular pulses to synchronise each step of the processor

  5. Which statement describes the stored program concept?

    • Each program is stored on a separate processor, so the programs run one after another
    • Instructions are only stored on the hard drive and must be re-entered each time the computer starts
    • Instructions and data are both held in memory, so the computer can run a program in sequence
    • Programs must be printed on paper before a computer can read the instructions in them

  6. What does a bus do inside a computer?

    • It sends the user's input directly to the internet without passing through the processor
    • It stores data permanently so that it is available when the computer is switched on
    • It carries data, addresses or control signals between components such as the processor and memory
    • It converts digital signals into an analogue form for the user to hear on speakers

  7. Why does a high-level program need to be translated before a computer can run it?

    • The processor can only understand instructions written in a spreadsheet format
    • The computer can only run programs that have been saved on a removable USB drive
    • The program must be converted into pictures before the processor can display them
    • The processor only understands machine code made of binary instructions

  8. What is the difference between a compiler and an interpreter?

    • A compiler checks spelling in the program, while an interpreter checks the speed of the processor
    • A compiler deletes the source code after it runs, while an interpreter keeps a copy
    • A compiler runs only on tablets, while an interpreter runs only on desktop computers
    • A compiler translates the whole program before it runs, while an interpreter translates line by line

  9. Which term describes a program written in binary machine code?

    • Source code, which is typed by a programmer into a text editor before it is compiled
    • Pseudocode, which describes the steps of an algorithm in plain language before coding
    • High-level code, which is written in English-like words that the user can read easily
    • Machine code, which the processor can execute directly

  10. What does the clock speed of a processor determine?

    • The total number of programs that can be stored on the hard disk drive at one time
    • The number of cycles, or steps, the processor can carry out each second
    • The number of users who can log in to the computer at the same moment in time
    • The maximum size of a file that can be opened in a word processor on the device

  11. When a program is run, where are its instructions held while the processor works through them?

    • In the graphics card, which fetches each instruction and passes it to the processor
    • In random access memory, so they can be fetched quickly
    • On the hard disk drive only, where they are read one at a time by the processor
    • In the processor's program counter, which holds the complete program in one register

  12. What is an assembly language?

    • A high-level language that uses plain English sentences to describe the program steps
    • A set of rules for describing how two networked devices should communicate with each other
    • A language used only for designing web pages, using tags to define the layout
    • A low-level language that uses short mnemonics which map closely to machine code

  13. Which instruction would a processor use to move data from one memory address to a register?

    • A display instruction, which sends the contents of a register to the monitor
    • A sleep instruction, which pauses the program until the user presses a key
    • A load instruction, which copies data from memory into a register
    • A store instruction, which copies data from a register into a printer buffer

  14. Why is the address bus needed?

    • It carries the memory address that the processor wants to read from or write to
    • It carries the image data from the graphics card to the monitor for display on screen
    • It carries the user's keystrokes from the keyboard to the operating system software
    • It carries the power supply signal from the motherboard to the processor and memory

  15. A pupil says that a processor with four cores can run four instructions at exactly the same time. Which is the most accurate response?

    • This is false, because the number of cores only changes how much data the memory can hold
    • This is true for all programs, because the operating system always splits tasks evenly
    • This is broadly true, as each core can process its own instructions, but the programs must be written to use them
    • This is false, because a processor with four cores can only ever run one instruction at once

  16. What does the control unit do during the fetch-decode-execute cycle?

    • It stores the results of every calculation permanently on the hard disk for later use
    • It converts images from the graphics card into digital sound that plays through speakers
    • It holds all the data the user has typed into the program since it was started
    • It directs the flow of data and signals between the processor, memory and other components

  17. Which statement about cache memory is correct?

    • It is a large, slow memory that is used only to store the operating system files
    • It is a type of storage that keeps files safe when the computer is switched off
    • It is a small, fast memory close to the processor that holds frequently used data and instructions
    • It is a network address that identifies a device on a local area network

  18. Why do instructions need to be stored in memory rather than being typed in at the keyboard each time?

    • So the keyboard can give the processor its clock pulse, which keeps the cycle steady
    • So the processor can fetch and execute each instruction automatically in the required order
    • So the monitor can display each instruction as the processor carries it out on screen
    • So the hard drive can compress the instructions into a smaller file for the user

  19. What is the purpose of a register inside a processor?

    • It is a list of all the programs that have been installed on the computer by the user
    • It is a connection point that joins the processor to the graphics card in the computer
    • It is a small, very fast storage location that holds data or instructions being worked on
    • It is a large store of files that the user saves for later access on the computer

  20. Which list shows the stages of the fetch-decode-execute cycle in the correct order?

    • Fetch, execute, decode
    • Fetch, decode, execute
    • Decode, fetch, execute
    • Execute, fetch, decode

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