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10 Dec 2025

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23 pages

Understanding Electricity - National 5 Physics

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charlotte @charlotte_cxtgfaytiu

Electricity forms the backbone of modern technology, from powering your smartphone to lighting your home. Understanding how electrical... Show more

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Physics Data Reference Sheet

Your National 5 Physics data sheet is basically your best mate during exams - it's packed with all the crucial values you'll need for calculations. You don't need to memorise these numbers, but you absolutely need to know how to use them.

The sheet includes speed of light values for different materials like3.0×108m/sinairlike 3.0 × 10⁸ m/s in air, gravitational field strengths for planets Earthsis9.8N/kgEarth's is 9.8 N/kg, and loads of material properties like specific heat capacities and melting points. Water's specific heat capacity of 4180 J/kg°C⁻¹ is particularly important - it's why water is so good at storing heat energy.

Quick Tip Get familiar with where everything is on this sheet before your exam. You don't want to waste precious time hunting for values during a test.

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Units, Prefixes and Scientific Notation

Getting your units right is absolutely crucial in physics - mess these up and your brilliant calculation becomes worthless. The SI units you'll use most are metres (m), kilograms (kg), seconds (s), joules (J), and newtons (N).

Scientific notation and prefixes save you from writing ridiculously long numbers. Instead of writing 0.000001, you can use 1 × 10⁻⁶ or simply 1μ (micro). The key prefixes are giga (G) = × 10⁹, mega (M) = × 10⁶, kilo (k) = × 10³, milli (m) = × 10⁻³, and micro (μ) = × 10⁻⁶.

Remember Always convert everything to standard SI units before doing calculations - it'll save you loads of headaches!

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Circuit Components and Symbols

Every electrical component has a specific job and a standard symbol that you need to recognise instantly. Cells and batteries provide the electrical energy that drives everything, whilst resistors control how much current flows through the circuit.

Lamps convert electrical energy into light, switches control whether current can flow, and variable resistors let you adjust the current flow. Think of a variable resistor like a volume control on your headphones - it gives you precise control over the circuit's behaviour.

Drawing circuit diagrams properly is essential - always use a ruler and the correct symbols. Your diagrams need to be clear enough that someone else could build the actual circuit from your drawing.

Pro Tip Practice drawing circuit symbols until they become second nature - you'll need this skill for every electricity question!

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Series vs Parallel Circuits

Understanding the difference between series and parallel circuits is absolutely fundamental to electricity. A series circuit has just one loop - if you break the circuit anywhere, everything stops working. It's like old-fashioned Christmas lights where one bulb going out killed the whole string.

Parallel circuits have multiple branches, and this is where things get interesting. If one branch fails, the others keep working perfectly. This is why your house lights don't all go out when one bulb blows - they're wired in parallel.

The advantage of parallel circuits is obvious when you think about it - imagine if your bedroom light going out meant your kitchen light stopped working too! That's exactly what would happen with series wiring.

Real-world connection Almost everything in your house uses parallel circuits - from lights to plug sockets to your phone charger.

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Electric Charge and Current

Electric current is simply the amount of charge flowing past a point every second. Think of it like water flowing through a pipe - current tells you how much water passes a specific point each second.

The relationship is beautifully simple I = Q/t, where I is current (amps), Q is charge (coulombs), and t is time (seconds). When 24 coulombs flow past a point in 12 seconds, you get 2 amps of current.

Ammeters measure current and must be connected in series with whatever you're measuring. This makes sense - to measure how much water flows through a pipe, you'd put your measuring device in the pipe, not beside it.

Memory trick Think of current as "electrical traffic flow" - ammeters count how many charges pass by, just like traffic counters on roads.

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

AC vs DC Current

The difference between alternating current (AC) and direct current (DC) is all about direction. In DC circuits, electrons flow steadily in one direction from negative to positive, like water flowing down a river.

AC current is completely different - the electrons constantly change direction, flowing back and forth 50 times every second in the UK. It's like a river that changes direction 50 times every second!

An oscilloscope shows this difference clearly DC appears as a straight horizontal line, whilst AC creates a wave pattern. Your phone battery provides DC, but the mains electricity in your house is AC.

Think about it AC is used for mains electricity because it's much easier to change voltage levels for efficient long-distance transmission.

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in
National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in
National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in
National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

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Anna

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Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

 

Physics

81

10 Dec 2025

23 pages

Understanding Electricity - National 5 Physics

user profile picture

charlotte

@charlotte_cxtgfaytiu

Electricity forms the backbone of modern technology, from powering your smartphone to lighting your home. Understanding how electrical circuits work, how current flows, and how to measure electrical quantities is essential for any physics student and opens doors to countless... Show more

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

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By signing up you accept Terms of Service and Privacy Policy

Physics Data Reference Sheet

Your National 5 Physics data sheet is basically your best mate during exams - it's packed with all the crucial values you'll need for calculations. You don't need to memorise these numbers, but you absolutely need to know how to use them.

The sheet includes speed of light values for different materials like3.0×108m/sinairlike 3.0 × 10⁸ m/s in air, gravitational field strengths for planets Earthsis9.8N/kgEarth's is 9.8 N/kg, and loads of material properties like specific heat capacities and melting points. Water's specific heat capacity of 4180 J/kg°C⁻¹ is particularly important - it's why water is so good at storing heat energy.

Quick Tip: Get familiar with where everything is on this sheet before your exam. You don't want to waste precious time hunting for values during a test.

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Units, Prefixes and Scientific Notation

Getting your units right is absolutely crucial in physics - mess these up and your brilliant calculation becomes worthless. The SI units you'll use most are metres (m), kilograms (kg), seconds (s), joules (J), and newtons (N).

Scientific notation and prefixes save you from writing ridiculously long numbers. Instead of writing 0.000001, you can use 1 × 10⁻⁶ or simply 1μ (micro). The key prefixes are: giga (G) = × 10⁹, mega (M) = × 10⁶, kilo (k) = × 10³, milli (m) = × 10⁻³, and micro (μ) = × 10⁻⁶.

Remember: Always convert everything to standard SI units before doing calculations - it'll save you loads of headaches!

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Circuit Components and Symbols

Every electrical component has a specific job and a standard symbol that you need to recognise instantly. Cells and batteries provide the electrical energy that drives everything, whilst resistors control how much current flows through the circuit.

Lamps convert electrical energy into light, switches control whether current can flow, and variable resistors let you adjust the current flow. Think of a variable resistor like a volume control on your headphones - it gives you precise control over the circuit's behaviour.

Drawing circuit diagrams properly is essential - always use a ruler and the correct symbols. Your diagrams need to be clear enough that someone else could build the actual circuit from your drawing.

Pro Tip: Practice drawing circuit symbols until they become second nature - you'll need this skill for every electricity question!

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Series vs Parallel Circuits

Understanding the difference between series and parallel circuits is absolutely fundamental to electricity. A series circuit has just one loop - if you break the circuit anywhere, everything stops working. It's like old-fashioned Christmas lights where one bulb going out killed the whole string.

Parallel circuits have multiple branches, and this is where things get interesting. If one branch fails, the others keep working perfectly. This is why your house lights don't all go out when one bulb blows - they're wired in parallel.

The advantage of parallel circuits is obvious when you think about it - imagine if your bedroom light going out meant your kitchen light stopped working too! That's exactly what would happen with series wiring.

Real-world connection: Almost everything in your house uses parallel circuits - from lights to plug sockets to your phone charger.

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Electric Charge and Current

Electric current is simply the amount of charge flowing past a point every second. Think of it like water flowing through a pipe - current tells you how much water passes a specific point each second.

The relationship is beautifully simple: I = Q/t, where I is current (amps), Q is charge (coulombs), and t is time (seconds). When 24 coulombs flow past a point in 12 seconds, you get 2 amps of current.

Ammeters measure current and must be connected in series with whatever you're measuring. This makes sense - to measure how much water flows through a pipe, you'd put your measuring device in the pipe, not beside it.

Memory trick: Think of current as "electrical traffic flow" - ammeters count how many charges pass by, just like traffic counters on roads.

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

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AC vs DC Current

The difference between alternating current (AC) and direct current (DC) is all about direction. In DC circuits, electrons flow steadily in one direction from negative to positive, like water flowing down a river.

AC current is completely different - the electrons constantly change direction, flowing back and forth 50 times every second in the UK. It's like a river that changes direction 50 times every second!

An oscilloscope shows this difference clearly: DC appears as a straight horizontal line, whilst AC creates a wave pattern. Your phone battery provides DC, but the mains electricity in your house is AC.

Think about it: AC is used for mains electricity because it's much easier to change voltage levels for efficient long-distance transmission.

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

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By signing up you accept Terms of Service and Privacy Policy

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

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Join milions of students

By signing up you accept Terms of Service and Privacy Policy

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

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Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

National 5
Physics
Electricity
Summary Notes National 5 Data Sheet
Speed of sound in materials
Speed of light in materials
Material
Speed in

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

We thought you’d never ask...

What is the Knowunity AI companion?

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

0

Smart Tools NEW

Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines

Mock Exam
Quiz
Flashcards
Essay

Most popular content: Resistance

Most popular content in Physics

Most popular content

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.9/5

App Store

4.8/5

Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user