68. AQA GCSE (8525) SLR11 – 3.4 Applying logical operators in tr

What triggers the fire alarm according to the scenario?

• A fire officer manually turns it on

• Both temperature and manual smash need to occur simultaneously

• Temperature inside the building rises above 60 degrees Celsius or someone smashes a fire-alarm glass panel

• Temperature inside the building drops below 60 degrees Celsius

Answer explanation

The fire alarm is triggered when the temperature inside the building rises above 60 degrees Celsius or when someone smashes a fire-alarm glass panel.

What can a fire officer do in the given scenario?

• Increase the temperature threshold for the alarm

• Shut off the fire alarm regardless of other conditions

• Smash the glass panel without triggering the alarm

• Activate the fire alarm manually

Answer explanation

The fire officer can shut off the fire alarm regardless of other conditions, as it is a valid action in the given scenario.

Which logic gates are mentioned as necessary for the GCC exam?

• NOT, AND, OR, XOR

• NOR, XOR, XNOR

• AND, OR, NOT

• NAND, NOR, XNOR

Answer explanation

The necessary logic gates for the GCC exam are NOT, AND, OR, and XOR, as mentioned in the question.

What is the initial state of the inputs in the logic diagram?

• All inputs are 1

• All inputs are 0

• Inputs are a mix of 0s and 1s

• The state of inputs is not specified

Answer explanation

The correct initial state of the inputs in the logic diagram is that all inputs are 0, as specified in the answer choices.

What happens when the temperature rises above 60 degrees Celsius?

• The OR gate outputs a 0

• The NOT gate outputs a 1

• The AND gate receives two 1s and outputs a 1

• The fire alarm remains off

Answer explanation

When the temperature rises above 60 degrees Celsius, the AND gate receives two 1s and outputs a 1, which is the correct answer choice.

What is the result when someone smashes the fire alarm glass panel?

• The NOT gate outputs a 0

• The AND gate receives two 1s and outputs a 1

• The fire alarm does not go off

• The OR gate outputs a 0

Answer explanation

The correct answer is that the AND gate receives two 1s and outputs a 1, triggering the fire alarm when someone smashes the fire alarm glass panel.

What does the NOT gate do in the scenario?

• Activates the fire alarm

• Inverts the input from the fire officer

• Increases the temperature threshold

• Turns off the fire alarm directly

Answer explanation

The NOT gate inverts the input from the fire officer, meaning it changes the input signal from true to false or vice versa.

How many initial inputs are there in the logic diagram?

• Two

• Three

• Four

• Five

Answer explanation

The correct answer is 'Three' because there are three initial inputs in the logic diagram.

What are the intermediate outputs in the logic diagram labeled as?

• I and J

• D and E

• E and F

• G and H

Answer explanation

The intermediate outputs in the logic diagram are labeled as E and F, as indicated in the correct answer choice.

How is the output from the OR gate represented in the truth table?

• As A

• As B

• As F

• As E

Answer explanation

The output from the OR gate is represented as 'E' in the truth table, making option 'As E' the correct choice.