Question 1:

The plastic layers on mains cables are used to prevent the flow of electric current from the wire inside to anything outside (and to protect the wire from damage).
That means plastic acts as an electrical insulator.

Correct answer: D. electrical insulator

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 2:

The safety device that limits the current flow in a plug is the fuse.
It contains a thin wire that melts and breaks the circuit if the current exceeds a safe value.

Correct answer: A. fuse

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 3:

The earth wire is connected to the metal casing of a metal toaster.
This ensures that if a fault occurs and the live wire touches the metal casing, the current safely flows to earth via the earth wire, preventing electric shock.

Correct answer: C. metal casing

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 4:

The correct answer is A.

The earth wire provides a low-resistance path for electric current to flow to the ground if the live wire accidentally touches the metal casing. This causes a large current to flow, which blows the fuse and disconnects the supply, preventing the user from receiving an electric shock.

Correct answer: A. prevents the user getting an electric shock in case the live wire touches the casing

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 5:

The correct answer is D. double insulated.

Devices with a plastic (non-conductive) casing that do not require an earth wire are called double insulated.
They are designed with two layers of insulation (basic + supplementary) or reinforced insulation, so an earth connection is unnecessary for safety.

Correct answer: D. double insulated

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 6:

We use the same formula:

Where:

• P=1.5 kW=1500 W

• V=240 V

Rounded, that’s 6.3 A.

Correct answer: B. 6.3 A

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 7:

For a hairdryer that draws 6.25 A during normal operation, the fuse rating should be the next standard size above the operating current, but not so high that it fails to protect against faults.

• 3 A fuse → would blow immediately (too low) ❌

• 5 A fuse → would also blow during normal use (too low) ❌

• 10 A fuse → can handle 6.25 A continuously, but will blow if a fault causes excessive current ✅

• 13 A fuse → technically works, but is higher than necessary; might not blow as quickly in a fault (less safe) ⚠️

The best and safest choice is the 10 A fuse.

Correct answer: D. 10 A fuse

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 8:

First, calculate the current drawn by the amplifier:

Now, select a fuse rating slightly above the normal operating current from the standard options: 1 A, 3 A, 5 A, 13 A.

• 1 A fuse → safely above 0.52 A, will blow if current exceeds 1 A (fault protection) ✅

• 3 A fuse → much higher than needed; may not blow quickly enough in a fault ⚠️

• 5 A or 13 A → too high, unsafe for a low-power device ❌

The correct and safest choice is 1 A fuse.

Correct answer: A. 1 A fuse

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 9:

The device described — a mains switching safety device found in nearly all homes that automatically turns off the circuit if the current gets too high — is called a circuit breaker.

Correct answer: B. circuit breaker

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 10:

The main advantage of a circuit breaker over a fuse is that it can be reset (switched back on) after it trips due to an overload, whereas a fuse must be replaced each time it blows.

Therefore, the best description is:

B. No fuses/parts need replacing if the current gets too high in any circuit

(The other options are either not true or not the main advantage.)

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.