2.4 Boolean Logic

• What is a logical operator?

  Symbols used to represent circuits of transistors within a computer
• What are the three most common logical operators?

  NOT, AND, OR
• What is the purpose of a truth table?

  To show all possible inputs and the associated output for each input
• What values are typically used in a truth table?

  Boolean values, usually 0 or 1
• What does the NOT logical operator do?

  Produces an output that is the opposite of the input
• What is another name for the NOT operator?

  Negation
• What is the symbol for the NOT operator?


  ¬
• What does the AND logical operator output?

  Outputs 1 only if both inputs are also 1
• What is another name for the AND operator?

  Conjunction
• What is the symbol for the AND operator?


  ∧
• What does the OR logical operator output?

  Outputs 1 if either input is 1
• What is another name for the OR operator?

  Disjunction
• What is the symbol for the OR operator?


  ∨
• What is the process for completing truth tables with multiple operators?

  • Work out each column from left to right
  • Use the preceding column values carefully
• How does the number of rows in a truth table change with additional inputs?

  The number of rows doubles with each new input
• How many rows are required for two inputs in a truth table?

  4 rows
• How many rows are required for three inputs in a truth table?

  8 rows
• How many rows are required for four inputs in a truth table?

  16 rows
• What is the procedure for drawing a logic diagram from a logical expression?

  • Draw NOT symbols or expressions in brackets first
  • Follow with AND and OR symbols as needed
• What types of questions might be asked in an exam regarding Boolean Logic?

  • Complete truth tables
  • Simplify expressions in truth tables
  • Identify logical operators in scenarios
  • Draw logic diagrams for expressions