• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5

# How does the number of coils on an electromagnet affect its strength?

Extracts from this document...

Introduction

How Does The Number of Coils On An

Electromagnet Affect Its Strength?

Aim: To find out how the number of coils on an electromagnet affects its strength.

Scientific Knowledge:

An electromagnet is a temporary magnet; the magnetic field only exists when an electric current is flowing. Any electric current produces a magnetic field, but the field near an ordinary straight conductor is rarely strong enough to be of practical use. A strong field can be produced if a wire is wrapped around a soft iron core and a current is passed through the wire. The strength of the electromagnet depends on how many coils you wrap round and how high the voltage is.

The area of force (magnetic field) surrounding a bar magnet can be shown by the lines of force as shown below, although these lines are no more real than the lines of latitude and longitude on a map or globe.

When opposite poles of a magnet are brought together, the lines of force join up and the magnets pull together.

When like poles of a magnet are brought together, the lines of force push away from each other and the magnets repel each other.

Electromagnets are used to lift large masses of magnetic material such as scrap iron.  Electromagnets are also found in electrical generators, electric motors, doorbells, circuit breakers, television receivers, loudspeakers, etc.

The factors that increase the strength of an electromagnet are;

• Increasing the number of coils, which adds more field lines and makes the electromagnet stronger.

Middle

Prediction:

I predict that as the number of coils are increased the magnetic field will become stronger, because each coil has its own magnetic field, so the more coils there are the more field lines there are which means it would be a stronger electromagnet. The electromagnet will become stronger if we add more coils because there are more field lines in a loop then there is in a straight piece of wire. In a solenoid there are a lot of loops and they are concentrated in the middle, as more loops are added the field lines get larger, therefore making the electromagnet stronger. The magnetic field becomes stronger because the magnetic field around a wire is circular and vertical to the wire, but the magnet fields from each of the turns in the coil add together, so the total magnetic field is much stronger. The magnetic field around a solenoid is much stronger than a bar magnets because each coil acts like a magnet when a current is passed through it, when the coils are repeated several times it is like having several mini magnets in a row, making it more stronger than bar magnet.

Apparatus:

Iron Nail

Power pack

Paper clips

Coil wire

Wires

Crocodile clips

Method:

1. Collect all the equipment and paper clips, demagnetise the nail by hitting it with a hammer
2. Connect everything together and put the voltage on the power pack to 4V
3. Wrap the coil around the iron nail 5 times and turn the power supply on
4. See how many paper clips it picks up then turn the power pack off

Conclusion

By looking at the graphs and lines of best fit, a few anomalous results. The first time we done the experiment we got one anomalous result, the rest of the results were quite near the line, I think this is because some of the paperclips got tangled together. In the second experiment there was only one anomalous result. I think this is because the metal was already magnetised before from the first experiment. On the third experiment there were two anomalous results, this is because the magnetism had built up from the two previous results making the third the most inaccurate result. This is mainly due to the fact that the electromagnets had not been demagnetised before each of the experiments.

If I could repeat this experiment I would demagnetise the magnet after each time I repeated the experiment, this would give a more accurate result, because I didn’t demagnetise the magnet the electromagnet kept increasing its magnetism each time. Also if I could do the experiment again I would do it much more quickly because as the metal heats up it slowly demagnetises the magnet. Another thing that I would change, is that I would change the voltage on the power pack instead of the coils, I would have done this at 1V, 2V and 3V because it would be another way of testing to see if my theory was right, by changing the continuous result. I would also change the way I conducted the experiment, instead of just dipping the paperclips into the pot, I would dangle them off each other. This would give me an accurate reading of how strong the electromagnets field is.

This student written piece of work is one of many that can be found in our AS and A Level Fields & Forces section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related AS and A Level Fields & Forces essays

1. ## Investigate four factors that may affect the strength for electromagnets: the number of turns, ...

4 star(s)

Keep these three conditions constant throughout the whole part. 3 Connect the circuit. 4 Set the sensor 5cm from the magnet 5 Turn on the switch and record 5 successive readings on the graphical calculator as 'X1 T' (since the reading changes all the time) 6 Turn off the switch and change only and increase the distance between the sensor and the magnet by 5cm.

2. ## To investigate the effect of current on the strength of an electromagnet field.

I will repeat each experiment three times for accuracy. Preliminary Work A number of preliminary experiments were carried out to ensure that we had a good range of readings and to identify any problems in the apparatus. These were the problems that occurred: * The beaker unbalancing.

1. ## Investigating a factor affecting the voltage output of a transformer.

Also, after V1=2V, there is no direct proportionality between V1 and V2. This is as the higher the voltage the higher the resistance. Yet increasing V1 does increase V2 up until a point where my graph appears to level off at V1=6.3V.

2. ## Investigating the factors affecting the strength of an electromagnet.

When varying the charge I will add an ammeter to the circuit to enable me to take accurate readings of charge. To actually test the strength of the electromagnet, I will lay it in a pile of paperclips and turn on the electromagnet via the power pack and see how many paperclips the electromagnet has been able to attract.

1. ## To see how the number of coils on an electromagnet affect its strength.

This means that the ends of the solenoid act like the North Pole and the South Pole of the bar magnet. Therefore, if the direction of the current is reversed the north and south poles will swap ends. If you look at one end of a solenoid, you can tell whether it is the north or the South Pole.

2. ## Einstein's theory of relativity.

The effect of gravity on light is also the reason why black holes are invisible. The gravitation in a black hole is so strong that light cannot escape from it. Physicists have known for more than a hundred years that when some elements are heated to incandescence they give off a pattern of spectral lines (coloured lines)

1. ## To calibrate an uncalibrated Hall probe and use it to investigate how the magnetic ...

The two bar magnets should be placed end-to-end to each other with opposite poles facing each other. They are separated by a distance d, as shown on the diagram. The distance can be measured using a metre ruler accurate to 0.5 cm.

2. ## Find out what kind of effect the strength of an electromagnet has if the ...

I decided this because I have access to accurate equipment to measure the current, when I change it. The other available variables will be kept constant throughout the experiments. Prediction I predict that if you increase the number of turns on the coil the electromagnet will be stronger.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to