65. AQA GCSE (8525) SLR11 – 3.4 Logic circuit diagrams

What does a NOT gate do to its input?

• Outputs true if at least one input is true

• Outputs true if both inputs are true

• Combines two inputs

• Reverses the input

Answer explanation

A NOT gate reverses the input, meaning it outputs the opposite of the input signal. If the input is true, the output is false, and vice versa.

What is required for an AND gate to output 1?

• Both inputs are 0

• Both inputs are 1

• At least one input is 1

• At least one input is 0

Answer explanation

For an AND gate to output 1, both inputs must be 1. This is because the AND gate only outputs 1 when both inputs are 1.

What condition must be met for an OR gate to output 1?

• Both inputs must be 1

• Both inputs must be 0

• At least one input is 1

• Both inputs are 1

Answer explanation

The correct condition for an OR gate to output 1 is when at least one input is 1, making the statement true.

How does an XOR gate differ from an OR gate?

• It requires both inputs to be 1 to output 1

• It outputs 1 if both inputs are 0

• It behaves exactly the same as an OR gate

• It outputs 0 if both inputs are 1

Answer explanation

An XOR gate outputs 0 if both inputs are 1, which is the key difference from an OR gate.

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

• The output is unchanged

• 1

• 0

• The gate does not accept a single input

Answer explanation

The output of a NOT gate when the input is 1 is 0, as the NOT gate inverts the input value.

Which logic gate is described as having its output on if either of its two inputs is on?

• XOR gate

• AND gate

• OR gate

• NOT gate

Answer explanation

The OR gate is described as having its output on if either of its two inputs is on, making it the correct choice.

What is the unique feature of an XOR gate when compared to an OR gate?

• It can only have one input

• It outputs 0 when both inputs are 1

• It outputs 1 when both inputs are 0

• It does not allow electrical current

Answer explanation

The unique feature of an XOR gate is that it outputs 0 when both inputs are 1, distinguishing it from an OR gate.

Which gate outputs 1 only when both its inputs are 1?

• XOR gate

• AND gate

• NOT gate

• OR gate

Answer explanation

The AND gate outputs 1 only when both its inputs are 1, making it the correct choice for this scenario.

What additional logic gates are introduced beyond GCSE level?

• NAND and NOR gates

• AND and OR gates

• NOR and XOR gates

• XOR and NOT gates

Answer explanation

Beyond GCSE level, NAND and NOR gates are introduced as additional logic gates, which are not covered at the GCSE level.

What does a NAND gate do?

• Combines the features of NOT and OR gates

• Reverses the output of an AND gate

• Outputs 1 if both inputs are 0

• Outputs 0 only if both inputs are 1

Answer explanation

A NAND gate reverses the output of an AND gate, producing 0 only if both inputs are 1.