Lesson 1.4.3b

1.4.3b Logic gates, truth tables, flip-flops, half and full adders Quiz: OCR Computer Science, Unit 4

20 questions

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Lesson 1.4.3b, Logic gates, truth tables, flip-flops, half and full adders: 20 multiple choice questions for the OCR Computer Science (H446), Unit 4: Data types, data structures and algorithms, written with Revision Ninja.

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The 20 questions

  1. Which logic gate outputs 1 only when both of its inputs are 1?

    • XOR
    • OR
    • AND
    • NAND
  2. Which logic gate outputs 1 when its inputs are different from each other?

    • AND
    • XNOR
    • XOR
    • NOR
  3. Which logic gate is created by placing a NOT gate directly after an AND gate?

    • NAND
    • XOR
    • NOR
    • XNOR
  4. What is the output of a NOR gate when both inputs are set to 0?

    • High impedance
    • Undefined
    • 1
    • 0
  5. What are the two output signals produced by a half adder circuit?

    • Bit and Byte
    • Data and Clock
    • Sum and Remainder
    • Sum and Carry
  6. Which logic gate calculates the Sum output in a standard half adder circuit?

    • XOR
    • AND
    • OR
    • NAND
  7. Which logic gate calculates the Carry output in a standard half adder circuit?

    • NAND
    • OR
    • AND
    • XOR
  8. How many inputs does a single full adder circuit accept?

    • 2
    • 3
    • 1
    • 4
  9. What is the primary function of a D-type flip-flop circuit?

    • Multiplying frequencies
    • Adding binary numbers
    • Inverting signals
    • Storing 1 bit
  10. What are the two main inputs to a D-type flip-flop?

    • Enable and Output
    • Sum and Carry
    • Data and Clock
    • Set and Reset
  11. On which event does a D-type flip-flop update its output value?

    • Clock edge
    • Clock cycle
    • Data change
    • Input pulse
  12. How many rows are required in a truth table for three logic inputs?

    • 3
    • 9
    • 8
    • 6
  13. Which of the following is considered a universal logic gate?

    • OR
    • NAND
    • AND
    • XOR
  14. What is the Boolean output expression for an XNOR gate given inputs A and B?

    • A OR NOT B
    • A AND NOT B
    • NOT (A AND B)
    • NOT (A XOR B)
  15. What are the Sum and Carry outputs of a half adder when inputs are A=1 and B=1?

    • Sum 0, Carry 1
    • Sum 0, Carry 0
    • Sum 1, Carry 0
    • Sum 1, Carry 1
  16. What are the Sum and Carry outputs of a full adder when A=1, B=1, Cin=1?

    • Sum 0, Carry 0
    • Sum 0, Carry 1
    • Sum 1, Carry 1
    • Sum 1, Carry 0
  17. Which computer memory component is constructed using arrays of flip-flops?

    • Dynamic RAM
    • Optical disc
    • Static RAM
    • Hard disk drive
  18. Which type of multi-bit adder passes the carry output directly to the next adjacent stage?

    • Ripple carry adder
    • Parallel sum adder
    • Series flip-flop adder
    • Lookahead subtraction unit
  19. What limit is created by propagation delay in a ripple carry adder?

    • Reduced bit width
    • Data loss
    • Increased power usage
    • Slower operating speed
  20. Which components are combined with an OR gate to construct a full adder?

    • One half adder
    • Two half adders
    • Three half adders
    • Two flip-flops

All OCR Computer Science quizzes