Hello, my name is Mrs. Merin and I'm so excited to be learning all about the position of switches.

And today we're going to be learning about open and close switches.

Let's begin.

Welcome to today's lesson from the unit changing circuits.

Your lesson outcome today is, I can explain how switches used in a simple circuit and can design and test my own switch.

Now I know that learning can sometimes be a little bit challenging, but that's okay because we are going to work really hard together and we are going to learn lots of fabulous new things.

Now here are your five key words for today's lesson.

Now, you don't need to write these down 'cause I am going to be going over them throughout today's lesson.

However, if you feel that it does help you, you can pause the video now and have a go at doing that.

Off you go.

Fantastic, well done.

And here are your keywords, definitions for today.

Now if you'd like, you can pause the video and write them down if it helps you, but it's not necessary because I am going to be addressing and going over these words throughout today's lesson.

But if it does help you, you can pause the video now and you can drop them down.

Off you go.

Fantastic, well done.

Now our lesson is split into two parts today.

Let's begin with the first part, switches.

Now switches play a really important role in our lives.

As well as turning bulbs, buzzers and motors on and off in simple circuits, switches control the circuits in many electrical appliances that we use every day.

Now I want you to think about this one and I'm sure that you're going to have so many answers for this one, but think about what switches have you used today.

So I'll give you five seconds to think about and list as many switches as you can think of.

Off you go.

Fantastic, well done.

So I'm thinking straight away for myself, I've used the switch to turn the light on and off.

I've used the switch to turn my laptop on.

I've used the switch to turn on my TV.

There's been so many switches that I have used today.

Now switches are used to control circuits and do you know how switches do this? So do you know how they control circuits? I'll give you five seconds to think about your answer and then we will carry on with our lesson.

Off you go.

Fantastic, well done.

So for electricity to flow around a circuit, there must be a complete loop from the electricity source through the components and back to the source.

So just like this diagram here.

Now switches turn a circuit off by making a gap where electricity cannot flow, like this one here.

Now I want you to think about this question.

What do switches do? Do they produce noise, control circuits, produce light, or provide the electrical push for circuits? I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

The answer is B, they control circuits.

Now traditional switches work by making a pair of conductors touch each other to complete a circuit or separate from each other to make a gap in the circuit.

So when the switch is closed, the conductors touch each other just like you can see in this diagram of a closed switch.

And this completes the circuits that the electricity can flow and there's nothing stopping it from not flowing all the way around the circuit.

So any devices, therefore, are on.

So for example, if you can, if you have a look in the room that I'm currently in, you can see that there is a light that is switched on.

So that means that the circuit is a closed circuit.

So the conductors in the circuit, in the room that I'm currently in with the light on are touching each other, allowing the light to be on, because the electricity can flow through that circuit.

Now when the switch is open, the conductors are separated from each other just like in this diagram here.

And this makes a gap in the circuit so that electricity cannot flow and any devices are off.

So if I was to now go and switch off the light in this room, it would mean that there is a gap in the circuit and the switch is open.

So the electricity is stopped from being able to flow all the way around the circuit.

Now I want you to think about this question before we move on.

How do switches stop electricity flowing around a circuit? Do they A, make a gap where the electricity then cannot flow, B, they make the electricity reverse direction, so go in the opposite direction.

Or C, they make a barrier which the electricity cannot flow through.

So I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

The answer is A, they make a gap where the electricity cannot flow.

Now in a basic switch, when the lever touches the contact point, the circuit is complete.

So we have got in the first diagram, it's a drawing of a basic switch.

We've got the terminals, we've got the contact point, we've got the lever.

So when it touches, when the lever touches that contact point, the circuit's complete.

Now in a toggle switch, the toggle is moved to the on position and this completes the circuit.

So some of you may have a toggle switch in your house somewhere, that you can, that looks very much like the diagram there.

Now when the toggle is moved to the off position, this creates a gap in the circuit just like a light switch in your house does.

Now slide switches, also found on appliances, are operated by sliding a lever from one position to another.

So I want you to just think about any appliances that you might have in your house that has a slide switch.

So automatically I'm thinking about the little lamp, the bedside lamp that my children have in their bedroom has a little sliding lever, an on and off sliding lever.

Are there any others that you might, that you can think of in your house? I'll give you five seconds to have a quick think, if you can think of any appliances that might use this slide lever.

Off you go.

Fantastic, well done.

So there might be other examples as well.

I have an electric candle and on the bottom of the electric candle it has this sliding lever as well.

Now here we have a drawing of a slide switch.

So you can see the terminal on the bottom and then the slider on the top.

So when the lever is in the on position, the two conductors touch each other and the circuit is complete.

Now, push button switches found in lots of electrical appliances have a button that is pressed and released.

So for example, I'm thinking about my toaster.

So when I think my toast is done, I can press a little push button which says cancel and the toast pops up.

And that's the push button there.

Or I'm thinking about my air fryer as well or even my microwave.

So a lot of you will have a microwave that has push button switches on it too.

So here is a photo of a push button switch and then we've got a drawing of a push button switch.

So we've got the terminal there at the bottom and then the button.

So when the button is pressed on, both terminals make contact in order to complete the circuits.

Now reed switches are made from two thin magnetic metal strips inside a glass tube.

So here we've got the terminal on either end, we've got the metal strip there and the glass tube.

Now when a magnet is held near the switch, the strips or the reeds touch each other and complete the circuit.

And when the magnet is removed, the reeds separate and there's a gap in the circuit turning any devices off.

So let's do a quick check-in of your learning so far.

When a switch is closed, A, conductors are separated from each other and electricity cannot flow.

B conductors touch each other and electricity can flow, or C, conductors touch each other and electricity cannot flow.

I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

So B, conductors touch each other and electricity can flow.

Now I want you to have a go at this first activity.

It says sort the cards into two groups, open switch and closed switch.

So we've got some statements here.

We've got the conductors are separated from each other so that open or close, the conductors touch each other, the circuit is incomplete, electricity can flow, the circuit is complete, electricity cannot flow.

Devices are on, devices are off.

So I want you to sort those cards into open and closed.

So I'd like you to pause the video now and have a go at that activity.

Off you go.

Fantastic, well done.

So open and off.

The conductors are separated from each other.

The circuit is incomplete, electricity cannot flow and devices are off.

And for a closed switch, the conductors touch each other, electricity can flow, devices are on and the circuit is complete.

Now we are on to the second part of your learning, innovative switches.

Now scientists and engineers collaborate to create new types of switches.

These switches still work by completing or making a gap in electrical circuits.

However, they do this in an unusual, in unusual and innovative ways.

Now, touch switches are touch sensitive just like the switches on a microwave and they rely on the pressure of a push from a finger pushing two conductors together to complete the circuit.

And these switches can control microwaves, cookers, and cashpoint machines at banks.

Now some touch switches rely on the fact that humans contain electricity.

Now electrical signals are used to send messages around our bodies, just like you can see in this diagram here.

For example, when we want to move a part of our body, our brain sends electrical signals to our muscles causing them to contract and produce movement.

And switches which rely on touch are often used to make choices on a screen such as smartphones and tablets.

So when a person touches the screen, the conductivity of their fingertips controls the way electricity flows within a circuit in the screen.

And this triggers a switch to open or close on the electrical device.

Now let's do a quick check-in of your learning before we move on.

So engineers have created innovative switches, which A, are sensitive to human touch.

B, work when electrical insulators are connected, or C, control the human body.

I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

The answer is A, they are sensitive to human touch.

Now Sophia says, when I was younger I made a simple switch using cardboard split pins and paper clips.

And Lucas says, I would like to work like an engineer to design and make a more innovative switch.

What kind of things might Lucas need? I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

So Sophia has some suggestions for Lucas.

She says, switches for simple circuits can be created from a range of everyday conductors and insulators such as cardboard, dough, metal bottle tops, paperclips, and kitchen foil.

Now Lucas here has built two simple circuits, each with a bulb and a cell.

And he says, I want to design and make an innovative switch connected to both circuits.

It will control the circuit so I can have each bulb lit separately or both lit together.

Now how might Lucas do that? I'd like you to have a really good think about this.

If you need to, you can pause the video.

Otherwise I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

So we will have a little think about Lucas's answer, but before we do that, let's just do a quick check-in of your learning.

So true or false, you can only make switches using materials bought from an electrical shop.

Is that true or is that false? I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

The answer is false.

Now let's see if you can justify your answer.

Is it because A, you cannot make switches, you have to buy them, or B, switches can be created from a range of everyday conductors and insulators.

Again, I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

And the answer is B, switches can be created from a range of everyday conductors and insulators.

Which statement below is true.

A, you only need electrical insulators to make a switch.

B, you need magnetic materials to make a switch.

Or C, you need both electrical insulators and conductors to make a switch.

Again, I'll give you five seconds to think about your answer.

Off you go.

Fantastic, well done.

The answer is C.

You need both electrical insulators and conductors to make a switch.

Now let's have a go at this activity.

So do you remember Lucas? He wanted to design and make an innovative switch to control both circuits and light one bulb at a time, but then also light both bulbs at the same time.

So I want you to think, how can we help Lucas to design and make this innovative switch? You're going to need to decide how to complete the circuit and you should make your switch from everyday conductors and insulators.

So think back to what Sophia said and what she suggested are everyday materials that can help us with that.

Okay, I'm going to give you some time now, so I want you to pause the video here and have a go.

Off you go.

Fantastic, well done.

So Lucas chose spoons and he taped the spoons to the wire.

So he says, I made my switch from stainless steel, teaspoons and wire.

There were three spoons.

When the middle spoon was placed in top of either of the spoons, one bulb would light up.

When I stacked all the spoons on top of each other, both bulbs lit up.

Now we are onto the summary of our learning today.

So switches are used to control circuits.

Traditional switches work by making a pair of conductors touch each other to complete a circuit or separate them from each other to break.

Engineers have created unusual switches which are sensitive to human touch.

Switches for simple circuits can be created from a range of everyday materials.

Now, I am so proud of how hard you have worked today.

Well done.

You've really used your critical thinking and you have learned lots of fabulous new things.

Well done.