Computer Science for IGCSE & O level - Boolean Logic (Section 1)

• 1

  Which logic gate provides the inverse of the output from an AND gate?

  回答

  (B)

  NAND gate
• 2

  What is the result of the expression (A AND B) OR (NOT A AND NOT B) in the provided image?

  回答

  (D)

  A XNOR B
• 3

  Which gate's output is 0 only when both of its inputs are 1?

  回答

  (A)

  AND gate
• 4

  Which of the following are considered universal gates?

  回答

  C

  D
• 5

  Which of the following logic gates implements the Boolean expression: Y = A ⋅ B ?

  回答

  (B)

  AND
• 6

  If A = 0 and B = 1, what is the output of an XOR gate?

  回答

  (B)

  1
• 7

  Which gate is often used for binary addition?

  回答

  (C)

  XOR
• 8

  Which type of logic gate implements the Boolean expression A AND B?

  回答

  (A)

  AND gate
• 9

  Which operation is the inverse of the OR operation?

  回答

  (B)

  NOR
• 10

  What does the acronym 'RPM' stand for in the context of the engine management system example?

  回答

  (A)

  Revolutions Per Minute
• 11

  In Boolean algebra, what is the meaning of A * B (or A AND B)?

  回答

  (B)

  A and B
• 12

  Which of the following logic circuits represents the given Boolean expression: Y = A OR (B AND C)?

  回答

  (A)

  A circuit with an AND gate, whose inputs are B and C. And the output of this gate is fed in an OR gate along with A.
• 13

  What is the result of A + 1 in Boolean algebra?

  回答

  (C)

  1
• 14

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

  回答

  (A)

  A value that can be either a 0 or a 1.
• 15

  Which of the following is equivalent to (A')' ?

  回答

  (A)

  A
• 16

  How many truth table rows are required for a 3-input logic gate?

  回答

  (D)

  8
• 17

  Which gate produces an output of '1' if and only if both inputs are '1'?

  回答

  (B)

  AND
• 18

  What does the term 'digital logic' refer to?

  回答

  (B)

  The use of discrete voltage levels to represent information
• 19

  If the output is 1 for A=0, B=1, and C=0, which of the following Boolean expressions could represent the corresponding logic circuit?

  回答

  (B)

  (NOT A AND B) OR (NOT C)
• 20

  In the context of logic circuits, what does 'binary' refer to?

  回答

  (B)

  A number system with a base of 2
• 21

  In a logic circuit designed to monitor the output of an engine management system, the output signal will go high (1) if either the exhaust temperature exceeds 400°C AND the air pressure is greater than 10 bar OR the water temperature is greater than 100°C.

  回答

  (D)

  The output signal will be high if the exhaust temperature exceeds 400°C and the air pressure is greater than 10 bar or the water temperature is greater than 100°C.
• 22

  What are the outputs of a 2 input XOR gate when inputs are '0, 0', '0, 1', '1, 0' and '1, 1' respectively?

  回答

  (A)

  0, 1, 1, 0
• 23

  What is the output of a XOR gate when the inputs are both the same?

  回答

  (A)

  0
• 24

  What is the effect of a NOT gate on an input signal?

  回答

  (B)

  It complements the input signal (inverts it).
• 25

  Which logic gate is represented by the expression (A + B)'?

  回答

  (B)

  NOR
• 26

  Given the following Boolean expression: Y = (A AND B) OR (NOT C). Which of the following logic circuits would correctly implement it?

  回答

  (B)

  A circuit with three inputs A, B and C, where A and B are AND'd, and C is NOT'd, and the two results are OR'd.
• 27

  Which gate provides the logical product operation?

  回答

  (A)

  AND gate
• 28

  In a digital circuit, what is the most common system for representing logic states?

  回答

  (B)

  Binary
• 29

  What does the term 'intermediate' refer to when discussing truth tables and circuit design?

  回答

  (B)

  Results within the truth table used to develop the final output.
• 30

  What is the output of an XOR gate if both inputs are 0?

  回答

  (A)

  0
• 31

  Which gate combines the inputs to produce an output if all inputs are true?

  回答

  (B)

  AND
• 32

  Which gate is equivalent to an AND gate followed by a NOT gate?

  回答

  (B)

  NAND gate
• 33

  What is the output of a NOR gate with inputs A=1 and B=1?

  回答

  (A)

  0
• 34

  Based on the truth table for a half-adder, if the inputs are A=1 and B=1, what are the values of the sum and carry outputs?

  回答

  (C)

  Sum = 0, Carry = 1
• 35

  What is the role of an OR gate?

  回答

  (C)

  To output 1 when at least one input is 1.
• 36

  Consider the engine management system scenario (Task 2). If the exhaust temperature is 400°C, air pressure is 11 bar and water velocity is 5 m/s, will the output (Y) be 1?

  回答

  (A)

  Yes
• 37

  Which gate's output is high only when all the inputs are low?

  回答

  (B)

  NOR
• 38

  What happens to the output of an AND gate if one of the inputs is permanently connected to '0'?

  回答

  (A)

  Output is always 0
• 39

  Which of the following is the correct symbol of the NOT gate?

  回答

  (B)

  A triangle pointing to the right with a circle
• 40

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

  回答

  (A)

  0
• 41

  What is the function of the 'carry' output in a full adder circuit?

  回答

  (A)

  To indicate if a sum overflows.
• 42

  Which is the logical expression for a NOR gate?

  回答

  (B)

  ¬ (A + B)
• 43

  Which of the following gates is known as the 'exclusive OR' gate?

  回答

  (C)

  XOR
• 44

  Which logic gate is also known as an inverter?

  回答

  (C)

  NOT
• 45

  If A = 0 and B = 1, then what is the output of an OR gate?

  回答

  (B)

  1
• 46

  Which gate outputs a '1' only if the inputs are different?

  回答

  (C)

  XOR
• 47

  Based on the examples, what are the possible outputs in the circuits shown?

  回答

  (B)

  0 and 1
• 48

  Which logic gate's output is LOW only when all inputs are HIGH?

  回答

  (C)

  NAND
• 49

  What is the role of an OR gate in the examples shown?

  回答

  (C)

  It outputs 1 if at least one input is 1.
• 50

  What is the output of a two-input AND gate if both inputs are 0?

  回答

  (A)

  0