Computer Science for IGCSE & O level - Boolean Logic (Section 10)

  • 1
    Which logic gate produces a low output (0) only when all inputs are high (1)?
    Risposta
    (D)
    NAND gate
  • 2
    Which logic gate is represented by the Boolean expression (A ยท B)'?
    Risposta
    (C)
    NAND
  • 3
    What is the output of a 2-input AND gate when both inputs are HIGH (1)?
    Risposta
    (B)
    1
  • 4
    What type of gate is needed to build a half-adder circuit?
    Risposta
    (B)
    AND and XOR gates
  • 5
    Which of the following statements describes the behavior of an XOR gate?
    Risposta
    (C)
    Outputs HIGH if the inputs are different.
  • 6
    What is the primary function of the truth table?
    Risposta
    (B)
    To depict the output for all input combinations.
  • 7
    Which of the following statements correctly describes a NOR gate?
    Risposta
    (C)
    Outputs HIGH only if all inputs are LOW.
  • 8
    What is represented in the last section of the image?
    Risposta
    (A)
    Key terms
  • 9
    What is the output of an XOR gate if both inputs are LOW?
    Risposta
    (A)
    0
  • 10
    In Boolean algebra, which symbol represents the OR operation?
    Risposta
    (A)
    +
  • 11
    Which of the following is the correct symbol for a NOR gate?
    Risposta
    (A)
    A gate shaped like a D with a curved side and a bubble on the output
  • 12
    What is the primary role of a truth table in digital logic?
    Risposta
    (C)
    To describe the functionality of a logic gate or circuit.
  • 13
    What is the simplified form of the logic expression: A AND (A OR B)?
    Risposta
    (A)
    A
  • 14
    If the inputs to an OR gate are A=1 and B=0, what will be the output?
    Risposta
    (B)
    1
  • 15
    Which of the following is a fundamental building block in digital circuits?
    Risposta
    (A)
    Transistors
  • 16
    If A and B are inputs to an OR gate and A=1, B=0, and the output is X, what is the value of X?
    Risposta
    (B)
    1
  • 17
    In a full adder, how many inputs are required?
    Risposta
    (C)
    3
  • 18
    What is the output of a 2-input AND gate if the inputs are A=0 and B=0?
    Risposta
    (A)
    0
  • 19
    Which is the correct Boolean expression for a NAND gate with inputs A and B?
    Risposta
    (B)
    (A . B)'
  • 20
    What is the simplified Boolean expression for A OR (A AND B)?
    Risposta
    (A)
    A
  • 21
    If the inputs to an OR gate are A=0 and B=1, what is the output?
    Risposta
    (B)
    1
  • 22
    Which logic gate inverts its input?
    Risposta
    (C)
    NOT
  • 23
    Which of the following gates can be used to implement the expression A'B + AB'?
    Risposta
    (B)
    XOR gate
  • 24
    If a logic expression is (A AND B) OR (C AND D), which gate would be involved in the final stage?
    Risposta
    (B)
    OR gate
  • 25
    What is the output of a 2-input OR gate when both inputs are HIGH (1)?
    Risposta
    (B)
    1
  • 26
    What is the purpose of De Morgan's Law in digital logic?
    Risposta
    (A)
    To simplify complex Boolean expressions
  • 27
    What is the simplified Boolean expression for the expression: A AND (A OR B)?
    Risposta
    (A)
    A
  • 28
    What is the output of a 2-input NOR gate if the inputs are A=0 and B=1?
    Risposta
    (A)
    0
  • 29
    Which of the following gate is represented by a half-circle, with a straight edge on the input side?
    Risposta
    (C)
    NOT
  • 30
    What is the logical operation performed by a NOT gate?
    Risposta
    (C)
    Inversion
  • 31
    If the inputs to an XOR gate are A=1 and B=1, what is the output?
    Risposta
    (A)
    0
  • 32
    Which of these is a universal gate?
    Risposta
    (C)
    NAND
  • 33
    A NOR gate's output is the inverse of what other gate?
    Risposta
    (B)
    OR gate
  • 34
    What are the two possible output values of a basic logic gate?
    Risposta
    C
    D
  • 35
    What is the output of a 2-input NAND gate if both inputs are 1?
    Risposta
    (A)
    0
  • 36
    Which gate is implemented as a negation of an AND gate?
    Risposta
    (D)
    NAND
  • 37
    If the inputs to an OR gate are A=1 and B=0, what is the output?
    Risposta
    (B)
    1
  • 38
    Which of the following is the logical equivalent of the expression (A AND B)?
    Risposta
    (C)
    NOT (NOT A AND NOT B)
  • 39
    A gate that outputs a '1' only when all inputs are '1' is an:
    Risposta
    (A)
    AND gate
  • 40
    The XOR gate produces a HIGH output if:
    Risposta
    (C)
    The inputs are different
  • 41
    What is the output of a 3-input AND gate when the inputs are A=1, B=0, and C=1?
    Risposta
    (A)
    0
  • 42
    What is the primary purpose of using logic gates in digital circuits?
    Risposta
    (B)
    To perform mathematical operations
  • 43
    What is a key advantage of using logic gates to perform calculations in a computer?
    Risposta
    (B)
    They operate at very high speeds.
  • 44
    Which gate's output is LOW only if all inputs are HIGH?
    Risposta
    (A)
    NAND
  • 45
    In the half adder circuit, what is the sum and carry when A=1 and B=1?
    Risposta
    (B)
    Sum = 0, Carry = 1
  • 46
    In a digital circuit, the '0' state is typically represented by:
    Risposta
    (B)
    A low voltage
  • 47
    What is the output of an OR gate if all its inputs are HIGH (1)?
    Risposta
    (B)
    1
  • 48
    In a given truth table, the input columns are labeled A, B, and C. What is the maximum number of rows required in this truth table?
    Risposta
    (B)
    8
  • 49
    A logic gate has two inputs, A and B. If the output is 0 when A=0 and B=1, what type of gate is it?
    Risposta
    (C)
    NOR
  • 50
    Which logic gate produces a '1' output when both inputs are '0'?
    Risposta
    (C)
    NOR