Hello, everyone, this is Mr. James, and I hope that you are feeling curious because it's that time again, it's time for us to learn some science together.

Here we go.

Our lesson today is from the unit, Changing Circuits, and we are going to be learning about circuit symbols and diagrams. Here's our learning outcome.

"I can use circuit symbols to represent components in a simple circuit diagram." So let's consider some of the key words that we're going to need to help us with our learning.

I'll say them, you can repeat them after me.

Circuit.

Component.

Circuit symbol.

Circuit diagram.

We'll have a look at what those words mean next.

You can read the meanings here for yourself and if you need to come back to them anytime, that's absolutely fine.

Got that? Great.

Let's go.

So today's lesson outline.

We're starting off by talking about circuit symbols, we'll go on to talk about drawing circuit diagrams, and we'll end with using circuit diagrams. Aisha is trying to describe her circuit to Jacob.

"I had a cell joined to a wire that was connected to a motor, connected to another wire, then back to the cell." Jacob's finding it hard to follow that description.

How could Aisha explain this more clearly to Jacob? What do you think? Pause the video now and have a little talk about that.

"Why don't you draw the circuit?" suggests Jacob to Aisha.

Aisha finds it hard to draw all of the components accurately.

What could she do? What do you think? Well, Laura suggests that she could photograph her circuit.

Not a bad idea.

Alex says, "She could ask someone who's good at drawing to draw her circuit." Aha.

Clever thinking, Alex.

Jacob says something different.

"You could use simple symbols to represent the different components in the circuit." We use symbols in lots of places in our daily lives.

A symbol is a mark, shape or picture that represents something particular.

They help everyone understand the same thing, even if they don't know the word for it.

We use these symbols in our maths lessons.

Do you recognise them? I'm sure you do.

What symbols can you think of that we see today? Pause the video and talk about this now.

Did you come up with some? I'm sure you did.

What about these? Do you recognise them? Hmm.

Do you know what they mean? Do you know what they represent? This one's easy, isn't it? We all need this sometimes.

The toilets.

Yes, recycling, the recycling symbol, it's on the boxes that we put out each week with our recycling in.

What about this one? An exclamation mark.

Hmm.

Yes, it tells us that there's a hazard or danger somewhere near.

And this one? Hmm.

No smoking.

Very familiar.

Circuit symbols are small images that represent different electrical components.

They allow everybody in the world to understand which components are used to build a circuit, even if they don't speak the same language.

What is the name of the small images used to represent different electrical components? Is it, a.

Circuit emojis, b.

Circuit icons, c.

Circuit symbols, or, d.

Circuit avatars? What do you think? That's right.

Circuit symbols.

How are circuit symbols useful? I'll read some ideas and you choose the one which you think explains best how circuits symbols can be useful.

a.

They allow everybody in the world to understand how a circuit is made.

b.

They make scientific writing look fun and entertaining.

c.

They allow you to add colour to brighten up documents.

Or, d.

They mean different things in each country.

So what do you think? How are circuit symbols useful? Yeah, they allow everybody in the world to understand how a circuit is made.

Now we're going on to Task A.

Here you're going to design your own circuit symbols for the components shown.

The symbols should be 2D, two dimensions, you need to do them in pencil, and don't colour them in.

I know it's tempting, but don't colour them in.

Are you ready? Off you go then, you'll need to pause the video now.

How did you get on with that? Did you come up with some good ideas, some good designs for circuit symbols? I'm sure you did.

Your designs may have looked like this or they may have been absolutely and completely different.

What do you think of these? We've got a bulb, a cell, a buzzer, a wire, a switch, and a motor.

Similar to yours? Hmm.

Right, now let's move on.

Next is drawing circuit diagrams. These are the circuit symbols we use for common components.

Can see the cell, the wire, the switch, the bulb, the buzzer, and the motor.

Take a moment to just look at those carefully and see if you can put them into your memories.

There are two different ways though of drawing a switch symbol.

Why do you think that is? Pause the video so you can just talk about that for a moment.

Well, what did you think? This one shows a closed switch and it makes a complete circuit, and this one shows an open switch, which breaks the circuit.

Did you think the same? The symbol for a cell needs to be drawn the correct way round.

The smaller line represents the negative terminal and the larger line represents the positive terminal.

Look at the terminals on this cell.

Which diagram shows the cells the correct way round, 1 or 2? Look closely.

Take a moment to do that.

Oh, yes, it's not 2.

If you have two cells working together as a battery, you draw more lines.

There you go.

Just like that.

For every cell you have, you need to draw one short thick line and one long thin line.

Just like this.

Aisha wants to use circuit symbols to show how her circuit is connected together.

This is her circuit.

This is her circuit diagram.

She didn't label the components as she'd used circuit symbols.

She's coloured in the light bulb and drawn lines to show that it's on.

Can you spot Aisha's mistake? Pause the video now.

What did you spot, I wonder? When we draw circuit diagrams, there are some rules which we should follow.

When we draw wires in a circuit, we should always use a ruler.

We represent each circuit in a rectangular shape or in a group of rectangular shapes.

Using these rules helps show the circuit information clearly and accurately.

It doesn't end up looking like a plate of spaghetti.

Aisha redraws her circuit following these rules.

Here we go.

There's the circuit and there's the circuit diagram that she drew.

Now we have the correct circuit diagram.

Not this, but this.

Better, isn't it? Much clearer.

Jacob builds a circuit like Aisha's, but he includes a motor instead of a bulb.

Here's his circuit.

And here's Aisha's diagram.

He wants to draw a circuit diagram like Aisha's.

What would be different in Jacob's diagram? What do you think? Instead of the bulb symbol, he's used the symbol for a motor.

Can you see that? There we are.

Not the bulb, but a motor.

There are some other rules to remember when we draw circuit diagrams. Use a sharp pencil.

Use a ruler for the straight lines, even the symbols.

There should be no gaps, each wire should touch the components.

So have a little look on that one, can you see where the wire lines have been broken, and it's much better, isn't it, in the green ticked one? The circuit should be large enough to read clearly, yes, this one is a little on the small side, and this one is much, much better.

Drawing circuit diagrams. Now can you match the circuit drawings below to the diagrams? Pause the video so you can do that now.

Did you manage to decide which was which? There you go.

Well done.

Now match the circuit diagrams to the mistake made on each one of them.

So can you see there that we've got the three circuit diagrams, a, b, and c, and below we have to decide which one's too small, which one hasn't used a ruler, and which one's used a blunt pencil.

Again, you need to pause the video while you do this.

And how did you get on? There we are.

Identify the mistake that's been made for each of the diagrams below and then draw a corrected version.

You're definitely going to need to pause the video while you do this, so you're going to identify the mistake and then draw your own corrected version.

Good luck with that.

You need to pause the video now.

How did you get on with that? Let's have a look.

Here's, a.

Look for the mistake.

Yes, it was coloured in.

It shouldn't have been coloured in, should it? And, b.

Ah-hah.

It's not really a rectangle, is it, so did you do yours as a nice rectangle? And c.

Yes, too tiny.

Much too tiny, too small.

And that is a much better size in the corrected one.

And now in, d.

It's the gaps between the lines.

Can you see them? They need to be joined up, don't they, as they are in the corrected one? e.

Hmm.

No ruler.

That's better.

The corrected one shows how it should look when drawn with a ruler.

And, f.

Hmm.

You don't need to label anything.

Those labels are unnecessary.

The symbols do the work for you.

Now draw a diagram, a circuit diagram, for each of these circuits.

Off you go.

You'll need to pause the video.

Gosh, you were busy.

Let's see, shall we? Are you ready? That's what you should have drawn.

Take a little look at those a moment.

Happy with that? I hope so.

Let's move on.

Final part of our lesson now.

Using circuit diagrams. Circuit diagrams are useful because they show how a circuit is connected together in a way that everyone can understand.

You can see an electrical engineer busy at work here.

Looks like a fun job, doesn't it? Scientists and engineers can use the diagrams to help them to help rebuild circuits that have been designed by other people.

Jacob and Aisha want to build the circuit shown in the circuit diagram here.

Where should they start? Well, first of all, they need to identify the components they need.

Then they need to build the circuit with the components in the correct order.

Some circuit diagrams look very similar, but are not the same.

What's similar and what's different about the two circuits shown here? Pause the video so you can talk about that now.

Yeah, they have the same components but the switch is in different places.

What's similar and what's different about the circuits shown here? Pause the video if you need to.

Ready? Yeah, this time they have the same components, but the cells are connected a different way around.

What's similar and what's different about the circuits shown now? Have another think.

Did you get it? Yeah, they've got the same components but one has an open switch and one has a closed switch.

What's wrong with the circuit that's been built from the diagram shown? You'll need to have a look at it and then decide on your answer.

Pause the video now so you can do that.

So what did you think? What was wrong with the circuit built from the diagram? Was it, a, that the switch is in the wrong part of the circuit, or, b, that it has an incorrect component included in the circuit, or, c, that the switch is in the wrong position, on or off? What did you think? Yeah, it's got an incorrect component in the circuit.

And did you spot what that incorrect component was? Yes, it's a buzzer, isn't it? It's a buzzer where there should be a bulb.

Which of the following circuits matches the circuit diagram shown here? Take a close look.

What do you think? Yeah, it's this one.

Time for Task C.

Build the circuit shown in the diagrams below.

There are six of them.

Then get a friend to check whether you've built them correctly.

You're gonna need to pause the video, of course, while you do that, so can you pause the video now? How did you get on? What did your friend think about your circuits? Did you build them correctly? "My circuits," Alex says, "were mostly correct, but in one I had a switch closed that should have been open." "I spotted that Alex had put the switch and the buzzer the wrong way round," noticed Aisha.

Let's sum up what we've learned today.

Circuit symbols are small images that represent different electrical components.

Circuit symbols allow everybody in the world to understand how a circuit's made.

Circuit diagrams show how components in a circuit are connected together.

Well, well done for all your circuit building and understanding of circuit diagrams today.

I hope you enjoyed your lesson and I will see you again soon.