This will assess your understanding of the knowledge gained in this topic.

Identify the circuit symbol

Select the correct circuit symbol for a switch

Fill in the blank: Current is the same everywhere in a _________ circuit

If A1 = 2.7A and A3 = 1.9A, what would A2 read?

If A2 = 1.2A and A3 = 1.9A, what would A4 read?

If V1 read 3V and each of the bulbs were identical, what would V3 read?

If V2, V3 and V4 each read 1.5V, what would V1 read?

Static is the build up of what?

Electricity Review

﻿Hi everyone, and welcome to the final video in the electricity and magnetism series. Before we start, I just want to say well done for putting in so much hard work and dedication in this topic. For this lesson, you're going to need a pen and some paper to write your answers on. If you haven't got that equipment, I'll give you the opportunity now to pause the video and go and grab it. Remember to turn your phone on silent so you aren't distracted throughout this lesson. And if you can find a quiet space for you to work and study where you won't be interrupted. So when you're ready, let's begin. So throughout this topic, we've split it into two sections. You've been going through the electricity section with Miss White and the magnetism session with me. So, in the previous lesson, you had a review of all the electricity material that you covered with Miss White. In this review session, we're going to have a look at all the magnetism material that you covered with me. So we'll start off by just having a look at what magnets are again, then looking at the magnetic fields, and finally, looking at electromagnets. So magnets, we've got a picture of a magnet below. We know that magnets can attract and repel other magnets. What do those two words mean again, remember attract means the magnets pull towards each other, and repel means the magnets push away from each other. So this force that makes magnets attract and repel is called magnetism. It's a non-contact force, what does that mean? Well, it means that the magnets don't have to be touching in order for that force of magnetism to be felt. So magnets can what and repel other magnets? Correct answer I'd like you to say to your screen after three. Three, two, one. Brilliant, magnets can attract and repel other magnets. Remember attract means the magnets pull together, and repel means they push apart. So this force is a non-contact force. What is the force called? Say the correct answer to your screen after three. Three, two, one. Brilliant, magnetism is a non-contact force. That's what causes our magnets to be attracted to each other and causes our magnets to be repelled. So magnetism is a non-contact force. So, what else is really important when we're looking at magnets? Well we know that they can attract and repel other magnets, so why is this? Well, each magnet has two poles, the north pole and the south pole. So in our diagram below, our north pole is in pink and our south pole is in blue. So, how does this affect whether magnets will attract or repel? Well, two unlike poles attract, so two unlike poles when brought together will attract. What do I mean by two unlike polls? I mean polls that are different from one another. So in our example below we're bringing together a south pole and the north pole. They are different to one another so they are unlike poles. What do unlike poles do? Unlike polls attract. On the other hand, two like poles repel, so two like poles will move further apart. What do I mean by two like poles, or two like poles are poles that are the same as each other. So in our example below we have two south poles, so they are two like poles. What do like poles do? They repel. So if you bring together two like poles, they will repel each other. So let's put this into practise, these magnets below will what? Will they attract or will they repel? Think about it, are they like poles on unlike poles? Say the correct answer to screen after three. Three, two, one. Brilliant, these magnets will attract. Why will they attract? Because they are unlike poles. Poles that are different to each other. Unlike poles attracts. Okay, what about this example here, will these magnets attract or repel each other? Correct answer states your screen after three. Three, two, one. Brilliant, the magnets will repel each other. Why will they repel each other? Well, we're bringing to south poles together, they are like poles, remember like poles repel. And what's going to happen in this example, will these magnets attract or repel? Say the correct answer to your screen after three. Three, two, one. Brilliant, these magnets will attract, why? Because we've got a north and a south pole being brought together. These are unlike poles. What the unlike poles do? They attract, well done. Okay, let's see if we can put that into practise then, pause the video and complete the independent tasks on your screen now. Okay, so let's go through the answers together. Two like poles repel, remember like poles are poles that are the same as one another. So for example if we have two north poles, they will repel. Two unlike poles attract. So if we have different poles for example, a north and a south pole, they will attract. And magnetism is a non-contact force. Well done if you've got all of those answers are correct. So we know how magnetic field work. We've had a look at the magnetic field lines and what they mean. Remember, the magnetic field always runs from north to south. So it goes from the north and runs to the south. The arrows on the magnetic field lines tell you which direction the magnetic field is going. Also remember that the magnetic field lines when they are closer together, show us that the magnetic field is strongest. So the magnetic field is strongest at the north and the south poles. So magnetic field lines run from? Correct answer to your screen three two one. Brilliant, north to south, they always run from north to south. So we can use these magnetic field lines to explain why like poles repel and unlike poles attract. So we've got two unlike poles in the example below. If you look at the magnetic field lines, they are running in the same direction. So the magnetic field lines running the same direction, which is going to mean that the magnets attract. So if the field line run in the same direction, the magnets attract. So unlike poles attract because the magnetic field lines run in the what direction? Correct answer say to screen, three two one. Brilliant, cause they run in the same direction, well done if you got that one correct. So why do like poles repel then? Well, we can explain it again using our magnetic field lines. So if you look at the example below, we've got two south poles. If you notice that magnetic field lines run in opposite directions, so if the magnetic field lines run in opposite directions, the magnet will repel. So if the magnetic field lines were in opposite directions, what happens, you're right the magnets will repel each other. So like poles repel because the magnetic field lines run in the what direction? Okay, so the correct answer say to screen, three, two, one. Brilliant, they run in the opposite direction. So when our field lines run in the opposite direction the magnets repel. So let's see if we can put that into practise. Pause the video and try the independent task on your screen. If you're struggling there are tips below the question. Okay, let's see how we got on. Pause the video and use the correct answers on your screen to mark and correct your own. Important things to note on this, the magnetic field runs from the north to the south pole. So make sure that you've got arrows on your magnetic field lines to show this. Also, the magnetic field lines will be closest at the poles. So let's have another look at electromagnets. We know that when a current is flowing through a wire, it creates magnetic field around the wire. If we coil our wire around an iron core, that makes an electromagnet which has a very strong magnetic field. We can increase the strength of this electromagnet. So one thing we can do is increase the number of coils. So we increase the number of coils that will increase the strength of the electromagnet's magnetic field. So we can increase the number of what? Three two one. Brilliant, we can increase the number of coils. And this will increase the strength of the what? Correct answer say to screen three two one, magnetic field, brilliant. So we can also increase the current of the cell. So we increase the current of the cell this will increase the strength of the electromagnet's magnetic field. So increasing the current of the cell will increase the strength of the electromagnet's magnetic fields. So we can increase the what from the cell? Three two one. Brilliant, we can increase the current from the cell. This will increase the strength of? Three two one. Brilliant, it will increase the strength of the magnetic field. So we can do a simple experiment to measure how the number of coils affects the field strength. So using our simple electromagnet which we've talked about in previous lessons, we can see how many paper clips the electromagnet will pick up. So with 10 coils, how many paper clips will the electromagnet pick up? We'll record how many it can actually pick up, and then we're going to repeat this but we'll change the number of coils. So we'll do 20 30 and 40. The stronger the magnetic field, the more paperclips the electromagnet will pick up. So, let's see if we can put that into practise. Pause the video and answer the questions on your screen now. So let's have a look at the answers. Three things we can do to increase the strength of the electromagnet. First thing we're going to do is we're going to add an iron core, and then increase the number of coils, and finally we will increase the current. Well done if you got those questions correct. Okay, we're going to have a look at some exam style questions now. Pause the video and try question one. Pause the video and have a go a question two Pause the video and have a go a question three. How did you get on? Use the marks scheme to mark questions one and two. Use the mark scheme to mark question three. Well done, you've reached the end of this lesson and we've also reached the end of this topic. Well done for working so hard throughout this topic. Before we go make sure that you click the next button and you answer the post lesson quiz. That's all from me, until next time.

This quiz will assess you on your knowledge of the magnetism topic.

Magnetism is a __________ force.

Will increasing the number of coils increase or decrease the magnetic field strength of an electromagnet?

Electromagnets are useful because __________.

The north seeking pole of a magnet points to __________.

If two south poles of a magnet are brought together they will _________ each other.

If two north poles of a magnet are brought together they will _________ each other.

If a north and a south pole are brought together they will ________ each other.

Magnetism Review

Review of key ideas from lessons 10-14 of the electricity and magnetism unit

In this lesson we will review what we have learned about magnetism.

Science

Y8 Science

Key Stage 3

Year 8

Magnetism review

Electricity and magnetism

Physics

THEME

UNIT

Circuits

Current & series circuits

Current & parallel circuits

Potential difference

Potential difference in parallel circuits

Resistance

Measuring resistance

Lewis Howard Latimer

Static electricity

Magnetic fields

Magnetic forces

Electromagnets

Uses of electromagnets

Electric motors

Electricity review

What is the unit for charge?

What is the unit for current?

Complete the sentence: Current is the rate of flow of ...

Current is measured by...

A circuit composed of a single loop is called...

A circuit composed of more than one loop is called...

Select the correct circuit symbol for a resistor

What particles move through the wires to create the flow of charge?

What is the role of the ammeter in a circuit?

What is the role of the voltmeter in a circuit?

Fill in the blank: Potential difference is __________ in a series circuit

If the potential difference of the cell is 1.5V and each bulb was identical, what would be the readings on V2, V3 and V4?

Select the correct unit for resistance

Select the correct equation for ohm's law (where 'x' represents multiply and '/' represents divide)

A bulb has a current of 2 A and a resistance of 6 Ω. What is the potential difference? Remember potential difference = current x resistance

A computer has a current of 0.75 A and a potential difference of 3.3 V. What is the resistance? Give your answer to 2 significant figures

Select the factors that INCREASE resistance in a wire (Tick 3 boxes)

A student wants to measure how temperature affects resistance of a wire. Identify the independent variable.

A student wants to measure how temperature affects resistance of a wire. Identify the dependent variable.

A student wants to measure how temperature affects resistance of a wire. Identify the control variable.

Where is the magnetic field the strongest?

Fill in the blank: Current splits at the junction in a _________ circuit

Lesson overview:Magnetism review

Electricity and magnetism: