• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

What factors affect the strength of electromagnetism?

Extracts from this document...


Sreekar Charlu VSP

Physics Coursework

What factors affect the strength of electromagnetism?



A home made magnet is essentially a metal core, with a wire coiled around it. The core should be a ‘soft’ metal, for example soft iron. A ‘soft’ metal is one that is easily magnetised and demagnetised, and a ‘soft’ iron core increases the field strength. A wire coil that carries current is called a solenoid, and this solenoid is wound around the soft iron core. When a current is passed through the circuit, and the coil, a magnetic field is produced at the centre. This aligns the particles in the iron core, which are tiny magnetic domains pointing in all directions in the absence of current, in one direction. A magnetic field is produced around the electromagnet – a magnetic field is a region where magnetic materials (e.g. iron and steel) and also wires carrying a current experience a force acting on them. Magnetism is said to be induced in the soft iron core, that is, the soft iron core becomes magnetised. It is electricity through the coil and the magnetism that it induces in the iron core, which give it the name electromagnet.

I used the book “Physics for You” by Keith Johnson.

De-magnetised metal

Magnetised Metal


There are numerous factors but I will talk about the three main factors.

  • The number of turns on the coil
  • The current through the coil
  • Material of core

Here, only one factor will be investigated, which is the current through the coil.

...read more.


  1. With sellotape secure the wire in place at each end of the core, but at the end tip of the magnet where you will be placing the Newton meter, leave that free of sellotape.
  1. Clamp the electromagnet using the wooden clamp stand.
  1. Using the variable resistor, measure 0.50A.
  1. Using the 1N Newton meter, place on top of electromagnet, which is sellotape free, and pull gently.
  1. Record result.
  1. Repeat steps 6→8, using the different currents.
  1. Once done, repeat whole experiment twice so that you have done it three times.

How to keep the experiment a fair test

  • While I alter my independent variable I will have to keep all the other variables constant, e.g. the number of coils: - if you change the number of coils while doing the experiment it can affect your results by either increasing or decreasing the force exerted.
  • I will have to use the same equipment all the way through, including the electromagnet because any piece of equipment may have a flaw in it, and if changed, can affect the results.
...read more.


        The experiment could be extended by doing it with a larger spread of currents and up to a higher level of currents. This would have tested the prediction even further and may have proved or disproved it conclusively.

        The experiment was a fair test because all the variables were kept constant except for the current (the test variable). The experiment was accurate in my opinion.

        There were no anomalous results. The evidence is definitely good enough to support my conclusion as they are clear and simple, but I have also explored the detail of my conclusion, and any contrast between my prediction and results.

        The prediction stated that the iron core held a certain limit for the amount of magnetic field it could exert, irrespective of whether I increased the current further or not. This would explain the predicted levelling off, which was expected by me to appear on the graph.

...read more.

This student written piece of work is one of many that can be found in our GCSE Waves 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

See related essaysSee related essays

Related GCSE Waves essays

  1. Marked by a teacher

    Is Sunbathing Good?

    4 star(s)

    (Wikiopedia - Malignant Melanoma) How the Skin Tans... Our natural skin colour is determined by skin pigment also known as melanin. When our skin is exposed to UV, cells deep in our skin begin a process where more melanin is produced.

  2. Peer reviewed

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

    4 star(s)

    I am sure that this conclusion is correct as there were no anomalous results or irregular differences between the number of paperclips attracted when more coils were added each time.

  1. is sunbathing good for you?

    Melanoma is a malignant tumour of melanocytes, which are found mainly in skin but also in the bowel and eye. It is one of the rarer types of skin cancer, but causes the majority of skin cancer related deaths. Despite many years of intensive laboratory and clinical research, the single

  2. How Does the Number of Coils On An Electromagnet Affect Its Strength?

    Reliability This is one of the methods, which are good because it was accurate and we used a power pack instead of batteries. Batteries run out after a short time and their current is inaccurate because they do not give out a constant amount as they run out.

  1. The aim of my experiment is to see what factors affect electromagnetism the most ...

    From these quotes I also know now that the magnetic field only occurs near and inside the coil wraps. Therefore magnetism will also be strongest in those same places. Plan- From my scientific knowledge I can make a reliable plan.

  2. Our aim for this experiment is to find out a method of increasing the ...

    You can straight away see the anomalous result in the first couple of results. You can see that they are not very precise as it is clearly shows no pattern between the increase of coils and the increase of the number of paperclips it is able to pick up.

  1. Investigation of electromagnetism

    The controlled variables are the voltage on the battery, the same soft iron core and the same wire. I kept all these variables constant so the investigating of the turns would not be influenced by other factors; I only altered the testing variable.

  2. Investigating the factors which affect the sideways displacement of a light ray through a ...

    How to collect results: Results table: angle I (degrees) reading 1 (mm) reading 2 (mm) average (mm) 0 10 20 30 40 50 60 70 80 Graph: Fair Test: We must make sure that the same equipment is used. For example if we take more than one lesson to do the experiment, the same glass block must be used

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