Computer Science for IGCSE & O level - Boolean Logic (Section 2)

• 1

  Which logic gate will produce a high output if and only if all inputs are low?

  回答

  (D)

  NOR
• 2

  What are the inputs to a half-adder circuit?

  回答

  (A)

  Two binary digits
• 3

  How many inputs does a two-input AND gate have?

  回答

  (B)

  Two
• 4

  In a logic gate, what does a 'high' signal typically represent?

  回答

  (B)

  1
• 5

  What is the simplified form of (A + 0) in Boolean algebra?

  回答

  (A)

  A
• 6

  What is the purpose of a carry bit in binary addition?

  回答

  (A)

  To indicate that an addition resulted in a sum greater than 1
• 7

  Which of the following Boolean expressions does the logic diagram represents?

  

  回答

  (A)

  ((NOT A) AND B) OR C
• 8

  What is the sum and carry-out of a half-adder if the inputs are A=0 and B=1?

  回答

  (B)

  Sum=1, Carry=0
• 9

  In the context of the examples, what is the primary benefit of using a truth table to verify a logic circuit?

  回答

  (B)

  It ensures that the circuit matches the logic statement.
• 10

  In a logic circuit, the output is high (1) if motor speed is > 3000 rpm AND bearing temperature is <= 80°C, OR water velocity is > 4 m/s. Which of the following statements correctly describes the logic?

  回答

  (C)

  The system outputs 1 if both motor speed and bearing temperature meet the conditions, or water velocity meets the condition.
• 11

  Which of the following is equivalent to the Boolean expression NOT (A OR B)?

  回答

  (A)

  NOT A AND NOT B
• 12

  In Boolean algebra, what does the '.' symbol represent?

  回答

  (B)

  AND
• 13

  Which of the following gates is the result of inverting the output of an OR gate?

  回答

  (C)

  NOR gate
• 14

  Which gate is the inverse of an OR gate?

  回答

  (C)

  NOR gate
• 15

  What is the purpose of a circuit diagram?

  回答

  (C)

  To graphically illustrate the components and their connections.
• 16

  If the output of a logic gate is 0 only when all inputs are 1, what type of gate is it?

  回答

  (B)

  NOR
• 17

  What would be the next step after writing down a logic expression from a truth table?

  回答

  (A)

  To create a logic circuit based on the logic expression.
• 18

  In the context of Boolean algebra, what does '1' typically represent?

  回答

  (C)

  True
• 19

  Which logic gate's output is the inverse of the output of an AND gate?

  回答

  (B)

  NAND gate
• 20

  If a logic circuit's output is high (1) only when all input conditions are met, which type of gate is it?

  回答

  (B)

  AND gate
• 21

  What is the output of a NOT gate if the input is 1?

  回答

  (A)

  0
• 22

  What is the complement of the Boolean expression A.B?

  回答

  (A)

  A' + B'
• 23

  What is the output of a 2-input AND gate if the inputs are 1 and 1?

  回答

  (B)

  1
• 24

  What is the term for a number system based on two digits (0 and 1)?

  回答

  (C)

  Binary
• 25

  What is the result of the expression NOT (A AND B) when A=1 and B=0?

  回答

  (B)

  1
• 26

  How many inputs and outputs does a full adder have?

  回答

  (C)

  3 inputs, 2 outputs
• 27

  In digital circuits, what does the term 'high' often represent?

  回答

  (B)

  1
• 28

  What is the output of an OR gate if both inputs A and B are 1?

  回答

  (B)

  1
• 29

  How are the three parameters related in the wood system example?

  回答

  (D)

  The result depends on which combination of the parameters satisfies a specific condition.
• 30

  Which of the following statements about a NOR gate is correct?

  回答

  (B)

  The output is HIGH if both inputs are LOW
• 31

  In the context of logic circuits, what is a 'high' signal typically represented by?

  回答

  (C)

  A binary 1
• 32

  If all input conditions are not met, what will be the output value in many of the scenarios described?

  回答

  (A)

  0
• 33

  How does the number of possible output states increase with each additional input in a logic gate?

  回答

  (A)

  It doubles
• 34

  Which gate yields an output of 0 if *any* of its inputs are 1?

  回答

  (D)

  NOR
• 35

  In the expression Y = (A AND B) OR C, which operation is performed LAST?

  回答

  (B)

  OR
• 36

  What is the result of the Boolean expression 0 + 1?

  回答

  (B)

  1
• 37

  Which of the following is the Boolean expression for a NAND gate?

  回答

  (D)

  (A . B)'
• 38

  What does the term 'logic' refer to in the context of logic circuits?

  回答

  (B)

  The mathematical principles that govern the circuit's behavior.
• 39

  Which of the following is the correct Boolean expression for a 2-input NOR gate?

  回答

  (D)

  NOT (A OR B)
• 40

  What is the function of the logic gates?

  回答

  (C)

  To process binary data
• 41

  What is the role of sensors in the logic circuit (exam-style)?

  回答

  (B)

  To convert real-world conditions into electrical signals for the input.
• 42

  What is used to verify the correctness of the logic circuit?

  回答

  (B)

  The truth table.
• 43

  What is the function of a 'full adder' circuit?

  回答

  (A)

  To add two single-bit binary numbers and a carry-in.
• 44

  What is the most simplified form of the boolean expression: A + A'B?

  回答

  (A)

  A
• 45

  The output of an AND gate is 0 if:

  回答

  A

  B
• 46

  A certain logic gate always gives the output 1 if the inputs are different. Which gate is this?

  回答

  (B)

  XOR gate
• 47

  What is an appropriate approach for the design of a circuit?

  回答

  (A)

  Start with a truth table, then create a logic expression, then draw the circuit.
• 48

  In the logic circuit examples, what is the primary purpose of using a truth table?

  回答

  (D)

  To determine the output values for all possible input combinations.
• 49

  What is the output of a NOT gate if the input is 0?

  回答

  (B)

  1
• 50

  What is a truth table mainly designed to show in the examples?

  回答

  (B)

  All possible outputs of a logic circuit for every input combination.