10 minutes maximum! Can you do it in 5?

1. Which of these gives the formula for calculating electrical power?

  • A. power = current x charge
  • B. power = current x voltage
  • C. power = voltage x resistance
  • D. power = voltage x charge
2+3. A student is comparing power banks to take on holiday.
The output of the most powerful one is 5V at 2.4 A maximum.

power bank
Eak K. from Pixabay

2. What is the maximum power output of this power bank?

  • A. 2.1 W
  • B. 0.48 W
  • C. 12 W
  • D. 4.8 W

3. A different power bank has a lower power output. If the voltage output is still 5V, how does this affect the current output and the energy transferred per second, compared to the first power bank?

 current energy transferred per second
A
 lower lower
B
 lower same
C
 same lower
D
 same same

 

4-6: The table below gives some information about 3 different cells. What are the missing values?

cells (batteries)
voltage max. current power
4. 1.5 V 0.2
5. 100 mA 1 W
6.
 6 V 300 mW
 

 

7-9: An electric kettle is rated as 240 V, 2 kW.

electrical kettls gif

7. What is the current used when switched on?

  • A. 120 A
  • B. 480 A
  • C. 0.12 A
  • D. 8.3 A

8. Which of the following gives the correct formula to calculate the electrical energy transferred to the kettle?

  • A. E = I x V x t
  • B. E = I x V x R
  • C. E = I x R x t
  • D. E = R x V x t

9. The kettle takes 2 minutes to boil. How much electrical energy has been used to heat the water?

  • A. 1 kJ
  • B. 4 kJ
  • C. 16 J
  • D. 240 kJ

10. The power bank in question 2 has an output of 5 V and a maximum current of 2.4 A. If it can last for 50 minutes before running out, what energy is stored in the power bank?

  • A. 3000 J
  • B. 600 J
  • C. 6000 J
  • D. 36 000 J
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A.I. response
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We do an A.I. search for each question, then store the response to that question on our server. No need to do multiple searches! Repeating the same A.I. request would have a much bigger carbon footprint.

Question 1:

The basic electrical power formula for a DC circuit is:

P=I×V

where

So the correct answer is B.


*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.
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Question 2:

Use the power formula:

P=V×I

Given:
V=5 V
I=2.4 A

P=5×2.4=12 W

So the correct answer is C.


*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.

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Our use of A.I. is environmentally friendly!
We do an A.I. search for each question, then store the response to that question on our server. No need to do multiple searches! Repeating the same A.I. request would have a much bigger carbon footprint.

Question 3:

Energy transferred per second = power P.

Given:

Step 1: Current effect
Since P=V×I, and V is the same,

I=PV

If P is lower, then I is lower compared to first bank.

Step 2: Energy transferred per second
Energy per second = power P.
Since power is lower, energy transferred per second is lower.

So both current and energy transferred per second are lower.

That matches option 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.

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Our use of A.I. is environmentally friendly!
We do an A.I. search for each question, then store the response to that question on our server. No need to do multiple searches! Repeating the same A.I. request would have a much bigger carbon footprint.

Question 4:

We use the power formula:

P=V×I

where P in watts, V in volts, I in amperes.

Row 4:
V=1.5 V, I=0.2 A

P=1.5×0.2=0.3 W

→ Missing value: 0.3 W


*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.

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Question 5:

We use the power formula:

P=V×I

where P in watts, V in volts, I in amperes.


I=100 mA=0.1 A, P=1 W

V = P/I = 1/0.1 = 10 V

→ Missing value: 10 V


*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.

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Question 6:

We use the power formula:

P=V×I

where P in watts, V in volts, I in amperes.

V=6 V, P=300 mW=0.3 W

I=P/V=0.3/6=0.05 A=50 mA

→ Missing value: 50 mA or 0.05 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.

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A.I. response
Our use of A.I. is environmentally friendly!
We do an A.I. search for each question, then store the response to that question on our server. No need to do multiple searches! Repeating the same A.I. request would have a much bigger carbon footprint.

Question 7:

We use the formula:

P=V×I⇒I=P/V

Given:
P=2 kW=2000 W
V=240 V

I=2000/240≈8.33 A

So the closest answer is 8.3 A.

Option D

*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.

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A.I. response
Our use of A.I. is environmentally friendly!
We do an A.I. search for each question, then store the response to that question on our server. No need to do multiple searches! Repeating the same A.I. request would have a much bigger carbon footprint.

Question 8:

The correct formula for electrical energy transferred is:

E=P×t

and since P=V×I, we have:

E=V×I×t

That matches option 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.

close cross
A.I. response
Our use of A.I. is environmentally friendly!
We do an A.I. search for each question, then store the response to that question on our server. No need to do multiple searches! Repeating the same A.I. request would have a much bigger carbon footprint.

Question 9:

We use the formula:

E=P×t

where P=2 kW=2000 W, and t=2 minutes=120 s.

E=2000×120=240,000 J=240 kJ

So the correct answer is D.


*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.

close cross
A.I. response
Our use of A.I. is environmentally friendly!
We do an A.I. search for each question, then store the response to that question on our server. No need to do multiple searches! Repeating the same A.I. request would have a much bigger carbon footprint.

Question 10:

We use the energy formula:

E=P×t

where P=V×I.

Step 1: Power

P=5 × 2.4 =12 W

Step 2: Time in seconds
50 minutes = 50×60=3000 s

Step 3: Energy

E=12 W×3000 s=36,000 J

So the correct answer is D.


*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.