Lesson video

Good morning, everybody.

It is Miss Simkin back for your next science lesson.

I hope that you have had a really lovely week and have been getting up to lots of fun stuff.

I've been doing lots of reading this week, and I actually learned a new fact.

Which I'm going to share with you just before we begin, because you know I love an animal fact.

I discovered this week that polar bears, big, white, fluffy polar bears, actually have skin that is pitch black.

Which is really cool.

I've obviously never seen a polar bear's skin before and that just really surprised me when I read that.

So, there's our fact before we begin and now let's start our lesson.

In this lesson about electricity, we are going to look at the different parts of an electrical circuit.

For this lesson today, you will need the following things.

You will need a piece of paper.

You will need a pencil, a colouring pencil, if you want to mark your work in a different colour.

And you will need a ruler.

We're also going to need these star words.

So I'm going to say them, and then you're going to say them.

The reason that we practise our star words is for two reasons, actually.

The first is that it helps them stick in your memory when you say them out loud.

And also it means that when you are sharing all the science facts and the great learning that you've done with your family or your friends or your normal teachers, that you will be able to say the words correctly.

Okay? So it's important that we practise.

So I'm going to go and then you're going to go.

Circuit.

Great.

Component.

Electricity.

Brilliant.

Okay.

I want to talk about what the word component means before we start.

We're going to be learning about electricity and circuits in the lesson.

But before we begin, let's talk about what a component is.

A component is another word for part.

Okay? So it just means the part of something.

So my finger is a component of my hand.

It's part of my hand.

And we're going to be looking at the different parts or components of circuits today.

This is what we're going to do today.

We're going to start with some recap from the last lesson.

We're going to look at electrical circuits and their main parts.

Then we're going to look at the rules for building electrical circuits.

And then I'm going to quiz you on how much you've learned and see if you can figure out why each of the circuits that I show you wouldn't work.

Let's start with our recap.

Here is a picture from last lesson.

Can you remember what we were learning last lesson? Write it down if you can remember.

You might even want to write a fact that you remember about it.

Great.

Last lesson we were learning all about static electricity.

And we learned why the adorable boy in this picture might have ended up with his hair sticking up like this.

We learned in our last lesson that all matter in the universe contains positive and negative parts.

And we call these positive and negative parts charge.

Normally these parts are balanced out, so we don't notice them.

However, sometimes they become unbalanced.

So an example that we looked at last lesson is when we rub a balloon on our hair, it causes the charges to become unbalanced.

And when they become unbalanced, we say that a static charge has built up.

Or we call it static electricity.

And in today's lesson, we're going to look at a different type of electricity.

So we're going to look at the electricity that we find in electrical circuits.

Electricity that's used most of the time is not the same as static electricity.

And this is because electricity that we use in electrical devices, like my phone, like the light bulbs on my ceiling, are always moving in a loop.

So the electricity in our devices is always moving in a loop.

One complete circle.

Therefore to allow electricity to flow, we have to create a loop known as an electrical circuit.

So an electrical circuit is a loop that allows electricity to flow.

I'm going to show you an example now of an electrical circuit and all the different parts that can be used to build it.

I'm going to start by showing you some of the different components or parts of an electric circuit.

And then I'm going to show you under the visualizer how we can just set those different parts up.

So the first and arguably one of the most important parts of an electrical circuit is this.

Okay? So in here we have what you might recognise as a normal battery.

Quite a big one.

And it's inside a battery holder.

Okay? This is the power supply for the whole circuit.

It's what causes the electricity to flow around the circuit.

Or it will do when it's all connected up.

In an electrical circuit we don't call this a battery.

We call it the cell.

Spelled like this.

You can see, cell.

Okay? So this is the cell of our circuit and it's the power supply.

Next component I'm going to show you is a wire.

So in every electrical circuit you have lots of wires.

So this is an example of one and they are what the electrical flow flows through.

Okay? Then the last component I'm going to show you for now is this.

This is a little light bulb.

And when the electricity flows through the filament, that's what we call the little metal wire inside a light bulb.

When the electricity flows through the filament, it causes it to light up.

Now I'm going to show you how we would connect those components in a circuit.

So, here you can see I've got my cell and I've got my light bulb.

I'm going to need a wire to connect them on this side and a wire to connect them on this side.

And then we're going to have a full loop of my circuit.

So I can stick one of my wires in this side of my cell.

And one of my wires in this side of my cell.

And then with this type of light bulb, I need to attach a little clip onto the end of my wire so that I can clip it onto my light bulb.

And you'll see once I've clipped it onto both sides, my light bulb will light up.

There you go.

So, there you go, it's off.

And it's on.

So that is an electrical circuit.

It's called a circuit because you can see there's a full circle or a full loop between the components.

I'm going to show you two more different components that you can find in an electrical circuit.

And then I'll put them into our example.

We can see how they work.

So this is a switch.

You can get lots of different kinds of switches, but this is one example.

So when the switch is like this it's off.

And when it's, oops, like this, the switch is on.

Okay? I'll show you what that looks like in a second.

When the switch is closed, the electricity can pass through it.

But when it's open, it creates a gap in the circuit.

So you can see the gap here.

It creates a gap in the circuit that stops the flow of electricity.

And so it switches the circuit off.

Then this is a buzzer.

Doesn't look very exciting until I plug it in.

And then you will be able to hear how this one works.

So with this component, when electricity flows through it, you can hear a buzzing noise.

I hope you'll be able to hear it on the video.

Is quite a high pitch.

Like kind of noise.

Okay.

Let me switch back down so you can see.

So the first thing I'm going to do is I'm actually just going to swap my light bulb out for my buzzer.

So to connect my buzzer I don't need the crocodile clips.

It's got these two parts.

So I can just put it straight in.

I'm hoping that you will be able to hear this when I put it in.

Listen very carefully.

You hear that squeaky noise? Okay.

So that's how my buzzer works.

Going to stop it now.

Now I'm going to add the switch in as well.

Now we need either the buzzer or the light bulb to show the switch working.

Otherwise there'll be nothing to prove when it's on or off.

Okay? Because when the circuit is on, I can hear the buzzer.

And when it's off, I can't hear it.

And the same with the light bulb.

So I'm going to add a switch.

Just move this down so you can see.

I'm going to start with my switch off.

Okay? Let me just turn this so it's a bit more clear.

There we go.

So you can see my switch is currently open.

When I move this part of my switch, I'm going to switch it on and you should be able to hear the buzzer.

Here we go.

Great.

So it all works.

And you can see, I still have a complete loop of my circuit.

You can see that this wire connects to this one.

This wire connects to this one and this wire connects to this one.

They connect in a full loop.

Let's try the switch with the light bulb.

Okay.

Let's see.

So my switch is currently open.

I'm going to close it and my light bulb comes up.

Brilliant.

On.

Off.

So those are the main components in an electrical circuit.

Brilliant.

Let's have a go at answering some questions on electrical circuits.

So question one.

What do we call the loop through which electricity moves? And question two, you have three pictures.

Which parts of the circuit do those pictures represent? Pause the video and complete the answers to those questions now please.

Fantastic.

Let's mark our answers.

So we call it an electrical circuit.

That's what we call a loop that electricity flows through.

And then these parts where wire, cell and switch, if you wrote battery that's okay.

'Cause it is a battery, but we call it a cell when it's in an electrical circuit.

So just correct your answer to cell, please.

Well done.

If you need some more time to correct these answers, pause the video and do that for me now.

The next thing that I'd like you to do is this.

So I've given you four different components along the side.

You've got buzzer, cell, light bulb and switch.

And I'd like you to match them up with the descriptions in this table, please.

So the descriptions say an object that makes a gap in the circuit to stop the electricity flow.

An object that lights up when electricity flows through it.

An object that makes a sound when electricity passes through it.

An object that provides the power supply for the circuit.

So you don't need to write out the whole description, although you can if you want.

All you need to do is to write buzzer and then the number of the description it matches up with.

So if you think it matches up with description number one, then you would just write buzzer one.

Pause the video and complete that for me now, please.

Great.

Let's take a look at number one is a switch in which is an object that makes a gap in a circuit to stop the electricity flow.

Number two.

An object that lights up when electricity flows through it is a light bulb.

Number three.

An object that makes us sound when electricity passes through it is a buzzer.

And number four.

An object that provides the power supply for the circuit is a cell.

Well done if you've got those correct.

Pause the video if you need to correct your answers in a different colour.

Brilliant.

Now we're going to look at some rules for building electrical circuits.

I'm going to show you another demonstration, but before I do that, could you please copy this table onto your piece of paper or into your books? So you have one column that says, does the circuit work when, and there are four options, and then a second column for Yes or No.

And as we're going through our next demonstration, you're going to be filling these things in.

Can you pause the video and write this table down for me now.

Remember to use your ruler to keep it nice and neat.

Let's test out these rules then of our electrical circuit.

So the first thing we're going to see is will our circuit work if there's not a complete loop.

So here is our circuit we were looking at before.

In fact, I'm going to take the switch out just so it's really easy to see the loop.

At the moment, we've got our cell, we've got our light bulb and we've got a complete loop.

If you start at one point on the circuit.

In fact I'll just push it so that you can see it even more.

There you go.

If you choose one person at the circuit to start on, you can see that there is a loop, if I follow it with my finger all the way round.

And there aren't any gaps, okay? Through the cell holder, what you can't see is that this wire is going in here and attaching to the end of this cell and then going through and coming out of this end.

Okay? So the flow of electricity, there's no gap in the cell holder.

And you can tell that the circuit is working because my light bulb is on.

So now if I make a gap in the circuit, is it going to work? I've made a gap in the circuit.

You can see the gap here.

Does it work? No, it doesn't work.

The light bulb is off.

So we've just proved that a rule about circuits.

They don't work if there's a gap in them.

So in your table where it says there is not a complete, it says, does the circuit work if there is not a complete loop, the answer is no it doesn't work.

So you can fill that in on your table now.

Let's have a look at some of the other rules.

Okay.

I'm going to put my circuit back together.

So now I've got a complete loop again.

'Cause we know that's one of our rules of the circuit.

You can see my light bulb is back on.

And now we're going to test if the circuit works if there's no cell.

So I'm going to take my cell out so it can't work.

Because I've made a gap in it.

We already know that rule.

And I'm going to add something into the circuit.

I put a buzzer in instead.

Does my circuit work? Is the light bulb on? No, it doesn't work.

Okay? So we need a power supply in order for our circuit to work.

So in your table, if it says, does the circuit work if there is no cell? The answer is, say it to your screen.

No, it does not.

Okay.

Let's check our next rule.

Next, I'm going to check if it works when the switch is off, but first of all, I need to rebuild my circuit so that I know that it does work again.

So we've got my light bulb back.

I'm going to add the switch in now.

There we go.

Sorry.

Now you can see the whole thing.

So my switch is on.

What happens when I turn my switch off? So that's off.

Fill in your table.

Does the circuit work? Yes or no.

When the switch is off.

And then the last thing that we're going to check is what would happen if I took one of these wires and I attached it here? I haven't pushed it in yet.

But let's just think about it.

I still have a complete loop if I do that.

At least a complete loop of wires.

Does my circuit work if it's only attached to one side of the component? Have a look at the light bulb.

What about with all the components? Awesome.

So these were the rules that we should have had written down that we discovered and we tested during that demonstration.

So does a circuit work when there is not a complete loop? No, it doesn't.

We need a complete loop for our circuit to work.

Does the circuit work when there is no cell? Nope.

We need a power supply for our circuit to work.

Does the circuit work when the switch is off? Nope.

When the switch is off, it means there's a gap in the circuit.

So it won't work.

When our switch is closed, we have a complete loop.

So it will work.

Does the circuit work when the wires are attached to only one side of an object? No.

That means, again, we don't have a complete loop.

The electricity cannot flow through the complete circuit if we do that.

So, no, it doesn't work.

Okay.

Using those rules, can you now fill in the gaps? There must be at least one mm.

There must be a complete mm for the electricity to flow.

The mm must be plugged into each object on one side and come out of the object on the other side.

And the mm must be closed to make it work.

If you haven't already have a go at filling in those gaps.

Pause the video if you need some time.

Great.

Let's check our answers.

For the first one, there must be at least one cell.

There must be a complete loop for electricity to flow.

The wire must be plugged into each object on one side and come out of the object on the other.

And the switch must be closed to make it work.

Well done if you got those correct.

Give yourself a tick if you did.

And if you didn't, no problem.

Just correct your answer in a different colour please.

Pause the video if you need more time to do that.

Great.

Next, I'm going to show you some pictures of different circuits that do not work.

And I want you to figure out why.

Okay? If you want, you can draw the circuit.

If you'd rather just write the reason, then that's absolutely fine.

What's wrong with this circuit? Pause the video and write it down.

Great.

Remember you can always look back at the four rules that you have written down because it's going to be one of those four rules that is broken each time.

Let's check our answers.

This circuit has a gap in the loop.

Well done if you spotted it.

Unless we have a complete loop, our circuit won't work.

I'm going to show you the next one.

This time we have an extra component.

So in our last circuit, we had a cell, light bulb.

In this circuit, we've got a cell, a light bulb and a switch.

But what's the problem? Pause the video and write it down.

Great.

We've got another gap in the loop again.

What about this one? So have a look.

See if you can figure out what each of the components are and see if you can find the problem.

Pause the video if you need more time.

We've got a cell that's missing this time.

There's a light bulb.

There's a switch.

But then the one that's circled green is not a cell.

It's a buzzer.

So that's our problem.

What's wrong this time? Look closely and pause the video if you need more time.

Well done if you spotted it.

This one, the wire is plugged into only one side of the light bulb.

You can see one of the ports on the other side is empty.

Okay.

What about this one? This one's quite hard to see it.

I'm going to make it bigger so you can look really closely.

If you've spotted it I'll be very impressed.

On this picture the switch is open.

So you can just about see that the black bit is pointing down, which means the switch is open and we don't have a complete loop.

Okay.

I've got one more for you.

What is the mistake this time? Well done if you've spotted it.

It's only plugged into one side of that component down there which is a buzzer.

Good job.

We're going to be looking at circuits lots in our next lesson.

So well done for all your hard work today.

If you would like to share a picture of your work with me, then I would always love to see it.

Please ask your parent or your carer to share your works on Twitter with the hashtag #LearnWithOak, and then I will be able to see them.

You've worked so hard today that Charlie has appeared.

Charlie, say hello.

Over there.

Good boy.

Watch this.

Touch! Oh, who's a clever boy? Have a nice day everybody.