Lesson 4.4.2.1

4.4.2.1 Finite state machines Quiz: AQA Computer Science, Unit 4

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 4.4.2.1, Finite state machines: 20 multiple choice questions for the AQA Computer Science (7517), Unit 4: Theory of computation, written with Revision Ninja.

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The 20 questions

  1. What defines the movement from one state to another in a finite state machine?

    • A loop
    • An output
    • A variable
    • A transition

  2. What two factors determine the next state in a state transition table?

    • State and input
    • State and output
    • Input and output
    • Start and finish

  3. What type of finite state machine produces outputs on its state transitions?

    • A pushdown automaton
    • A Turing machine
    • A Mealy machine
    • A Moore machine

  4. What is the main purpose of an FSM without output?

    • Generating output strings
    • Storing unlimited data
    • Executing recursive functions
    • Recognising languages

  5. How is the start state indicated in a state transition diagram?

    • Bold outline
    • Unattached arrow
    • Double circle
    • Dashed circle

  6. How is an accepting state represented in a state transition diagram?

    • Dashed circle
    • Single square
    • Double circle
    • Unattached arrow

  7. A machine accepts strings containing an even number of 1s, with its start state also accepting. Which string is accepted?

    • 10101
    • 1001
    • 1
    • 100

  8. In an even parity FSM, what state transition occurs from the even state on input 0?

    • Move to odd
    • Move to start
    • Loop to even
    • Transition to accept

  9. A Mealy machine outputs 1 when a 1 follows a 0. For the input sequence 0, 1, 1, 0, 1, what is the output sequence?

    • 11011
    • 01101
    • 01001
    • 00000

  10. How many states does a Mealy machine need to detect a 1 that follows a 0?

    • 3
    • 1
    • 2
    • 4

  11. An FSM tracks whether the last input was 0. What state is entered on receiving input 0?

    • Last input 1
    • Error state
    • Start state
    • Last input 0

  12. A machine has states S1, S2 and S3, with S1 going to S2 on a, S2 going to S3 on b, and S3 accepting. Which string is accepted?

    • abb
    • a
    • ba
    • ab

  13. What is the minimum number of states needed for a machine that accepts strings with an even number of 1s?

    • 2
    • 1
    • 4
    • 3

  14. In a state transition diagram, what does a self-loop labelled 1 on state S mean?

    • Output value 1
    • Reset to start
    • Stay in state S
    • Move to state 1

  15. Which string would be accepted by an FSM designed to recognise strings ending in 01?

    • 11010
    • 10100
    • 11001
    • 01110

  16. A machine has 5 states and accepts 2 input symbols. In a complete deterministic transition table, how many transitions are listed?

    • 5
    • 25
    • 7
    • 10

  17. What key advantage does a state transition table provide over a state diagram?

    • Shows all transitions
    • Faster execution speed
    • Unlimited state memory
    • Automatic output generation

  18. An FSM counting even 1s processes input 1, 1, 1, 0. Which state does it end in?

    • Even state
    • Accepting state
    • Start state
    • Odd state

  19. On what do outputs in a Mealy machine depend?

    • State only
    • Next state only
    • State and input
    • Input only

  20. In a Mealy machine diagram, where is the output action specified?

    • State node
    • Start arrow
    • Accepting double circle
    • State transition arc

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