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Get startedPhase 1: With an adult, cut a length of copper wire about 25 cm long.

Phase 2: Wrap the wire around your marker/tube to make a spring shape. Leave about 3 cm of wire straight at one end.

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COPPER WIRE

MARKER PEN OR TUBE

LEAVE 3 CM OF WIRE AT END

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English physicist and chemist Michael Faraday is credited with discovering electromagnetic induction. Induction means “makes something happen”. His worked proved that if you spin a wire coil in a magnetic eld you can generate electricity!

When electric and magnetic elds interact, a force is produced. This force can make things move. We can use Faraday’s discoveries to make our very own spinning motor!

SafetyYou should only do this activity with adult supervision. Neodymium magnets are very strong and can be dangerous if swallowed. Keep them away from small children and pets. Cutting the wire should be done by an adult. The ends of the wire can be a little sharp, so please take great care when handling it. Do not leave the magnets attached to the battery for more than a minute, as it can make them very hot. Monitor the heat of the batteries regularly. If the battery does overheat, do not use it again. Let it cool and then dispose of it safely.

You will need– An unused AA battery (not a

rechargeable or lithium battery)

– 2 neodymium magnets (the

diameter of these should not be

bigger than that of the battery)

– – 16 gauge uninsulated copper

wire (thinner wire will be easier

to shape but it is not as effective)

– Ruler

– A marker pen/tube that has a

slightly bigger diameter than the

AA battery

– – Scissors or wire cutters

– Needle nose pliers (optional)

Your mission

O 10 – 20 minsAdult supervision requiredDifficulty: VVVVV

Learning objectives– Make a homopolar motor

Make a Homopolar Motor

AQUiLA Industrial Revolution issue activity

Things to think about

rr Once you’ve got this working, can you try other shapes? The key thing is that the shape needs to balance on the tip of the battery, so symmetrical shapes work best! One of our favourites is to make a heart-shaped spinner! Some people eveven make Homopolar dancers! How could you make that work?

Phase 3: Take the wire off the marker/tube. Take the straight end that you left. You will need to bend it so that the spring can balance on the top of the magnet.

Phase 4: Place your neodymium magnets on the at end of the battery. It should be able tto stand up on a at surface. Place your spring over the battery and check that it can balance on the tip of it. It should not touch any other part of the battery, as this will prevent it from spinning.

The other end of the wire should be very close to the magnets at the bottom. If it isnot close enough, then it will not not close enough, then it will not work. The end of the wire should also go all the way around the magnets – it should encircle them. This is how you will get the most spin out of your motor.

IIf the spring is too long or too short then take it off and squash it or stretch it until it is the right length. Make sure you remove the magnets from the battery when you are adjusting the length, or they will get very hot.

Phase 5:WWhen your spring is just the right length, place the magnets back on the bottom of the battery. Place it on the table and balance your spring on the top of the battery. It may need a little nudge to get it to spin. If it doesn’t, then try turning the magnets the other way up. It can take a bit of ddling with, but it is worth it! Science is all about experimentation. Trying and failing is all part of it.

Phase 6: Revel in the glory of your own homopolar motor!

TITIP: This experiment makes batteries run out really quickly, so if your motor isn’t working, try changing the battery.

© AQUILA magazine. Written by Lynsey Chapple

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BENT OVER STRAIGHT END

BATTERY

COPPER WIRE SPRING

MAGNETS

TIP OF THE WIRE IS IN THE CENTRE OF THE SPRING

PINCH WIRE INTO A ‘V’ SHAPE TO BALANCE ON THE BATTERY. MAKE SURE THE ENDS OF THE WIRE ARE NOT TOUCHING THE MAGNETS, BUT ARE CLOSE TO THEM.