Hello, my name is Mrs. Mefren, and I'm so excited to be learning with you today.

Today we are going to be learning all about changing the volume of buzzers.

Welcome to today's lesson from the unit Changing Circuits.

Your lesson outcome today is, I can predict and test how to change the volume of buzzes in a circuit.

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're going to learn lots of fabulous new things.

Now we are going to be touching upon some of your previous learning about changing components and changing variables in a circuit.

So those lessons will help you with today's learning.

Now, you have got five key words today.

You don't need to jot these down because I am going to be referring to them throughout today's video.

However, if it does help you and you would like to jot them down, you can pause the video here and you can have a go at doing that.

Off you go.

Fantastic, well done.

And here are the definitions for those keywords.

Again, you don't need to write these down.

However, if it does help you, you are more than welcome to pause the video here and jot those down.

Fantastic.

Well done.

So let's begin with the first part of our learning today, which is scientists make predictions.

Now, Aisha and Jacob have been exploring variables in circuits, and variables are things which can be changed in an investigation.

So what are variables or the things that you could change in this circuit? I'd like you to pause video here if you need to.

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

Off you go.

Fantastic, well done.

So Aisha says, I could change the number of bulbs or cells, or the voltage of the cell battery or add different components.

And Jacob says, just remember that increasing the number and voltage of cells increases the push they provide to the circuit.

So what do you think Aisha and Jacob have found out about the effect of these variables on the brightness of a bulb in a circuit? So have a look at these, which is changing the voltage of the cell or battery, changing the number of components and changing the position of the bulb in the circuit.

So what do you think Aisha and Jacob have found out about the effects of these variables on the brightness of a bulb? Now, if you've done the previous two lessons, I want you to really reflect on what you found out in those lessons.

Okay, I'm gonna give you five seconds to think about your answer, but if you need longer, you can pause the video here.

Off you go.

Fantastic.

Well done.

So their results showed them that the higher the voltage, the brighter the bulb was, and the higher number of components there were, the dimmer the bulb.

But changing the position of the bulb didn't affect its brightness at all.

Now, because they were comparing things, they used a lot of words ending in E-R to describe the patterns that they found.

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

It says, test results show that increasing the number and voltage of cells in a circuit, a, decreases the push provided to the circuit, B, does nothing, C, depends on the type of cells, and, D, increases the push provided to the circuit.

So again, I'll give you five seconds to think about your answer, but if you need longer, you can pause the video here.

Off you go.

Fantastic.

Well, doing the answer is D.

It increases the push provided to the circuit.

Now, test results help scientists to make a prediction for a further investigation.

So to predict is when you say what you think is going to happen, and making a prediction allows scientists to test their scientific theories and their ideas.

Now, making and testing predictions also help scientists identify gaps in their understanding.

So if they make a prediction and it turns out to be wrong, it tells them that they might have misunderstood that scientific theory or that idea.

Now I want you to think about this.

So how can Aisha and Jacob use their findings about variables and bulb brightness to predict how changing variables will affect the volume of a buzzer? So think about how they can use those variables from the bulb brightness experiments to make a prediction about the volume of a buzzer.

So I'll give you five seconds to think about your answer, but if you need longer, you can pause the video and then you can come back once you're ready.

Off you go.

Fantastic, well done.

So before we go on to that answer, let's do a quick check-in of your learning.

And it says, why do scientists make predictions? Is it because, A, it helps them to present their results in graphs? Is it B, it allows them to set up further investigations, or C, it helps them to identify gaps in their understanding? So I'm going to give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

The answers are B and C.

So it allows them to set up further investigations, but it also helps them to identify any gaps in their understanding.

Now, I want you to have a go at task A.

So I want you to use what you've learned about variables affecting the brightness of a bulb to make predictions to answer these questions.

So how does increasing the voltage of a cell or battery affect the volume of a buzzer? How does changing the number of components in a circuit affect the volume of a buzzer? And how does changing the position of the buzzer in a circuit affect the volume of a buzzer? So I want you to think back to that experiment and what I share had found out what Aisha and Jacob had found out about the brightness of bulbs, and how they're affected by certain variables changing.

And I want you to use that to help you to make the predictions about the volume of a buzzer.

Now, I want you to begin each prediction with I predict that, and for each of them I want you to explain why.

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

Off you go.

Fantastic, well done.

So your predictions may look similar to these.

So you may say, I predict that increasing the voltage of a cell battery will make the buzzer louder 'cause it made the bulb brighter.

I predict that increasing the number of components in a circuit will make the buzzer quieter because it made the bulb dimmer.

And I predict that changing the position of the buzzer in the circuit will not affect its volume because it didn't affect the brightness of the bulb either.

Well done.

Now let's move on to the second part of your learning, which is the effects of variables on buzzers.

So Aisha and Jacob used their test results to make their predictions.

So Aisha says, we predict that increasing the voltage will make the buzzer louder.

Increasing the number of components will make the buzzer quieter, and changing the position of the buzzer will not affect the volume of the buzzer.

Now, do you agree with what Aisha said? Have a look at your predictions from task A and see whether or not they are the same or different to what Aisha has said.

Off you go.

Fabulous.

Well done.

So, Aisha says, how could we test our predictions? Now what would you do? What experiment? What could you do in order to test the predictions about the volume of a buzzer? Again, I'll give you five seconds to think about your answer, but if you need longer, you can pause the video.

Off you go.

Fantastic, well done.

So to test how variables in a circuit affect a buzzer, you need to start with a simple circuit.

So Jacob says we need to start with a simple circuit with cells.

Why isn't a buzzer? And then we should change one thing at a time to test each variable intern just like we did when we were testing out the brightness of the bulbs.

Now, what do you think children should observe or measure to test their predictions? Again, I'll give you five seconds to think about your answer.

If you need longer, that's absolutely fine.

You can pause the video here.

Off you go.

Fantastic, well done.

So they need to measure the volume of the buzzer.

Now, how could they measure the volume of this, of the buzzer? What could they use in order to help them get a scientific result for the volume of the buzzer? Again, I'll give you five seconds to think about your answer.

Off you go.

Fabulous.

Well done.

So they used a light sensor to measure light, so maybe they could use a sound sensor to measure the volume of the buzzer and sensors and apps to measure sound do exist.

We also have things called data loggers as well.

Now, why is this better? Why is it better to use a sensor on an app or using a data logger? Why is it better to do that rather than just listen to the buzzer and how loud or quiet it is? Again, I'll give you five seconds to think about your answer if you go.

So the reason why it is better than just deciding how loud a buzzer is just by listening is because it gives you an accurate scientific result.

So sensors and apps make more accurate and reliable measurements of sounds rather than just estimating from our hearing.

And sensors can be attached or built into data loggers, and apps use the microphones on tablets or mobile phones as the sound sensor, which is really quite amazing.

Now, volume of sound is measured in a unit called decibels, which is often shorted to dB.

Now, here is a question just to check your understanding.

Sensors and data loggers can be used to make and record accurate measurements of what, A, light, B, height, or C, sound? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

The answers are light and sound.

Now, when Aisha and Jacob test how variables in a circuit affect the volume of a buzzer, they will record their results.

Now, Aisha says, I wonder if the measurements we record will show what we thought was going to happen.

And Jacob says, we will need to compare the results from our tests with the predictions we made earlier.

Now, scientists evaluate results to compare what was expected in an investigation to what actually happened.

So why do scientists evaluate the results of an investigation? Is it A, to make measurements more accurate? B, to compare what was expected, what actually happened, or C, to use different types of equipment like sensors and data loggers? So again, I'll give you five seconds to think about your answer.

Okay, off you go.

Fantastic, well done.

The answer is B, to compare what was expected to what actually happened.

Now, the children plan to investigate if their predictions were correct by planning an investigation to answer these questions.

Number one, how does increasing the voltage of a cell or battery affect the volume of a buzzer? B, how does changing the number of components in a circuit affect the volume of a buzzer? And number three, how does changing the position of the buzzer in a circuit affect the volume of a buzzer? So this is Aisha and Jacob's plan.

They're going to build a simple circuit with one or two cells, a buzzer and connecting wires.

Now they're going to check that the buzzer works and can be heard when the circuit is complete.

So they need to, that's really important to make sure that that's working.

Now, number three, they're going to hold the sound sensor phone or tablet next to the buzzer when it buzzes and record a measurement of the volume of the sound in decibels.

So they're going to do that as soon as they've built that simple circuit and checked that the buzzer works.

Then they're going to draw a diagram of the circuit and record the sound volume in a table.

Then they're going to change a variable in the circuit, and they're going to repeat steps three and four so that they can record whether or not this buzzer is getting louder or quieter.

So I want you to carry out an investigation like Aisha and Jacob, and I want you to record your results in a table.

So you might use a table like this one.

So you've got the variable that's been changed.

First, the components that you're going to use, a diagram of the second.

So that section needs to be bigger.

A prediction.

So what do you predict is going to happen when this variable is changed? And then you are going to use your data logger or your SoundSense app in order to record the buzzer volume in decibels.

So this is a great way to really keep track of your investigation and make sure that you are doing it accurately, and that you're only changing one variable at a time as well.

So that's really, really important.

Otherwise, you're not going to get an accurate result of which variable actually have the most impact.

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

Off you go.

Fantastic.

Well done.

Okay, so let's have a look at these results.

These are Aisha and Jacob's results, and your results may look similar to these, so they've got the basic circuit there.

So they've got the one cell and they've got the one buzzer.

They've drawn a really simple diagram of that here, and they haven't put a prediction in because it's not needed yet.

And buzz volume has been 64 decibels.

Now, they've increased the voltage.

So what that means is they've now put in two cells rather than just the one.

And they've also added in an extra, sorry, and they've kept to the one buzzer.

Now they've drawn the circuit diagram here, and they've put their prediction as the buzzer is going to get louder.

So we've got 76 decibels here, which was the outcome.

So their prediction was correct.

Buzzer did get louder.

Then they've decided that they're going to increase the number of components.

So they've gone one cell, one buzzer, and one bulb.

So this time they've still got the one cell, they've still got the one buzzer, but they've increased it to one bulb as well.

They've drawn the diagram there, and you can see they've put the bulb next to the buzzer, and they have said that the buzzer is going to get quieter, and they were right because it went down to 36 decibels.

Now, they then decided that they were going to change the position of the buzzer.

So this is before the bulb.

So they use one cell, one buzzer, one bulb, and the buzzer volume they think will stay the same.

And they noted the buzzer volume as 36 decibels.

Then they put the position of the buzzer after the bulb and they predicted that it's going to stay the same, and it was 34.

So circuit three is shown on both sides because it was first used to test whether adding a bulb changed the volume then to test the effect of the position of the buzzer as well.

So now I'd like you to write a conclusion to explain how changing variables in a circuit affects the volume of a buzzer, and did results support your predictions? So I'd like you to pause the video here and I'd like you to have a go at doing that.

Off you go.

Fantastic.

Well done.

So, Jacob has written this, now your results might be similar or they might be different to Jacob's.

Jacob said, "Our predictions were correct.

Our data shows that increasing the voltage did make the buzzer louder and adding extra components and bulbs did make it quieter.

Just like with the bulb changing the position of the buzzer did not affect the volume of the buzzer." Now we are on to the summary of your learning today.

Increasing the number and voltage of batteries increases the electrical push they provide.

Test results help scientists to make predictions for further investigations.

Sensors and data loggers can be used to make and record accurate measurements of light and sound.

Scientists evaluate results to compare what was expected to what actually happened.

Now you have worked really, really hard today.

I am so proud of all of the work that you've done.

Well done.