Experiment Results - The Strength Of An Electromagnet

Aim – To find out what affects the strength of an electromagnet.

Prediction – I think that the less coils of wire there are on the magnet there are the stronger the magnetic field will be.

Hypothesis – I think this will happen because if there is a large amount of coils not much magnetism will get through whereas is thee is less, more will get through.

Plan - What I am going to do is to find out the strength of an electromagnet. I will do this by wrapping coils of wire around a nail, attach the nail to a power pack using crocodile clips to see how many paperclips it picks up.

The equipment I will use is

Nail

Paperclips

Wire coils

Power Pack

Crocodile clips.

The experiment needs to be a fair test so the coils should be an equal distance apart and the height I pick the paperclips up from should also be kept at the same height.

Here is my step-by-step method.

1. Wrap coils equally around nail and connect to power pack.
2. Hold nail 5cm above the table and see how many paperclips it picks up
3. Add the next amount of coils.

Continue doing this until you have got up to a hundred coils then repeat steps 1, 2 and 3 again twice.

I am going to keep the distance in which I pick the paperclips up constant but vary the number of coils on the nail. I am going to add 10 coils each time until I reach 100.

Results table for the number of paperclips picked up

Number of coils	1st time	2nd time	3rd time	Average number of paperclips
10	1	2	2	2
20	3	3	3	3
30	4	3	2	3
40	6	4	4	5
50	4	3	2	3
60	5	5	5	5
70	5	6	2	4
80	5	4	5	5
90	6	5	4	6
100	7	5	3	6

Above is a results table showing my results, including the average score for each number of coils.

Conclusion

In our practical we found out that the more coils there are wrapped around the nail, the stronger the electromagnet is.

My results show that 10 – 30 coils around the nail wasn’t very powerful as it only picked up 1 – 4 paperclips but 50 – 100 coils was more powerful as it picked up 4 - 7 paperclips.

The line on my graph goes up and down, but stays straight at 20- 30 coils. The line got higher towards the end of the graph and the finished straight at 90 – 100 coils. My results don’t show any particular pattern but it does go up straight, then across straight then up and then down and then up and down again, then it goes straight up and across.

On the 2 points that is a high number of paperclips picked up, I think they are wrong. At them points I think there was just a slight power surge and on my graph I have circled those points. I think they should be lower down and on my graph I marked where I think they should really be in an x pink cross. In a yellow pen I drew what I think the line should have looked like. It still doesn’t have any particular pattern but goes in a straight line that goes up gradually at the end. My hypothesis was wrong, as was my prediction. I turned out that the more number of coils there are wrapped around the nail the stronger it as, therefore it picks up more paperclips.

Evaluation

I think me and my partner (Narissa Watkins) carried out the practical very well, we used the equipment as it was supposed to be used, there wasn’t any safety precautions needed and we got the best results obtained that we could.

The accuracy of my results is good, I used the equipment right and carefully. Most of my results are mostly the same, 10 – 40 coils picked up paperclips in the range of 6 – 1 and 50 – 100 picked up paperclips in the range of 2 – 7.

2 of the results I obtained were odd as they were much higher than the other results, these were circled on the graph and changed to what I though they should have been.

To improve my investigation I think I could have obtained more results e.g. adding 5 coils until I reach a hundred. Also if we were using different power packs we could have tried it out with different voltages.