What is Boolean logic ?

Boolean logic is used in computer science and electronics to make logical decisions using values that are either TRUE or FALSE (often represented as 1 or 0).

Logic gates are a visual way of representing a Boolean expression .

The AND gate returns TRUE only if both inputs are TRUE , otherwise it returns FALSE.

The OR gate returns TRUE if either input is TRUE , it returns FALSE only if both inputs are FALSE.

The NOT gate reverses the input value - NOT TRUE = FALSE, NOT FALSE = TRUE.

What is a truth table ?

A truth table is a tool used to visualise the results of Boolean expressions by representing all possible inputs and associated outputs.

True or False? In the exam, any valid notation can be used for Boolean expressions.

True. In the exam, any valid notation can be used in Boolean expression questions like T/F, 1/0, V for OR, etc.

State the truth table for the AND gate.

A B A^B 0 0 0 0 1 0 1 0 0 1 1 1

State the truth table for the OR gate.

A B A v B 0 0 0 0 1 1 1 0 1 1 1 1

Why are Boolean operators combined?

Boolean operators are combined to produce more complex expressions called logic expressions , using brackets to clarify the order of operations.

A logic diagram is a visual representation of combinations of Boolean operators within a logic circuit.

What is the purpose of a truth table?

A truth table is used to visualise the results of Boolean expressions by representing all possible inputs and associated outputs.

State the meaning of the expression: Q = NOT(A OR B)

The expression Q = NOT(A OR B) means Q is the output of a NOT gate , which takes the output of an OR gate with inputs A and B .

True or False? In the exam, logic circuits may have a maximum of 3 inputs and 1 output.

True. In the exam, logic circuits will be limited to a maximum of 3 inputs and 1 output.

True or False? P = (A OR B) IF NOT C is an example of combining Boolean operators

False. P = (A OR B) IF NOT C is NOT an example of combining Boolean operators. IF is not a valid Boolean operator

How many rows are needed for a truth table with 3 inputs?

For a truth table with 3 inputs (A, B, C), 8 rows are needed (2^3 = 8).

What notation is typically used in truth tables?

Truth tables typically use 1 for TRUE and 0 for FALSE values.

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Boolean Logic Diagrams (OCR GCSE Computer Science)

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What is Boolean logic?

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What is Boolean logic?
Boolean logic is used in computer science and electronics to make logical decisions using values that are either TRUE or FALSE (often represented as 1 or 0).
logic gates
Logic gates are a visual way of representing a Boolean expression.
AND gate
The AND gate returns TRUE only if both inputs are TRUE, otherwise it returns FALSE.
OR gate
The OR gate returns TRUE if either input is TRUE, it returns FALSE only if both inputs are FALSE.
NOT gate
The NOT gate reverses the input value - NOT TRUE = FALSE, NOT FALSE = TRUE.
What is a truth table?
A truth table is a tool used to visualise the results of Boolean expressions by representing all possible inputs and associated outputs.
True or False?
In the exam, any valid notation can be used for Boolean expressions.
True.
In the exam, any valid notation can be used in Boolean expression questions like T/F, 1/0, V for OR, etc.
State the truth table for the AND gate.
A
B
A^B
0
0
0
0
1
0
1
0
0
1
1
1
State the truth table for the OR gate.
A
B
A v B
0
0
0
0
1
1
1
0
1
1
1
1
State the truth table for the NOT gate.
A
¬A
0
1
1
0
Why are Boolean operators combined?
Boolean operators are combined to produce more complex expressions called logic expressions, using brackets to clarify the order of operations.
Logic diagram
A logic diagram is a visual representation of combinations of Boolean operators within a logic circuit.
What is the purpose of a truth table?
A truth table is used to visualise the results of Boolean expressions by representing all possible inputs and associated outputs.
State the meaning of the expression: Q = NOT(A OR B)
The expression Q = NOT(A OR B) means Q is the output of a NOT gate, which takes the output of an OR gate with inputs A and B.
True or False?
In the exam, logic circuits may have a maximum of 3 inputs and 1 output.
True.
In the exam, logic circuits will be limited to a maximum of 3 inputs and 1 output.
True or False?
P = (A OR B) IF NOT C is an example of combining Boolean operators
False.
P = (A OR B) IF NOT C is NOT an example of combining Boolean operators. IF is not a valid Boolean operator
How many rows are needed for a truth table with 3 inputs?
For a truth table with 3 inputs (A, B, C), 8 rows are needed (2^3 = 8).
What notation is typically used in truth tables?
Truth tables typically use 1 for TRUE and 0 for FALSE values.