Factors affecting the strength of an electromagnet

Aim

In this investigation I am going to find out what factors affect the strength of an electromagnet. I will do this by changing different factors of the investigation and seeing what affect they have.

Background Information

Electromagnets are a solenoid, a coil of wire, with a ‘soft’ iron inside.

A magnetic field is created around the wires of the solenoid as the current flows through it.

The magnetic field strength is increased by the ‘soft’ iron core, as iron is magnetically ‘soft’, meaning it changes easily between being magnetized and demagnetized.

As iron is ‘soft’ it is perfect for electromagnets which need to be turned on and off.

Some key factors that may affect the strength of the electromagnet are;

• The size of the current, if you increase the current then the electromagnet will be stronger as more electricity will be passing through it, therefore will make it stronger and able to lift more weight.
• The number of turns the coil has, if the number of turns is more then the magnetic field around the electromagnet will increase, making it stronger. If there are less turns in the coil then the electromagnet will be weak as there are less magnetic fields, therefore will lift less weight.
• The core-If the core is iron, which is soft, and changes easily between being magnetized and demagnetized then the electromagnet will work better than having a steel core which is ‘hard’ and retains its magnetism.

* Switch the power on and turn it up until there is enough current to lift one paperclip. (4 volts)

** Switch on the power and turn it up until there is enough current to lift one paperclip. (4 volts)

Step 3

* Increase the current by 2 volts and measure how many paperclips have been lifted.

** Increase the number of turns in the coil by 5 and measure the amount of paperclips lifted.

Step 4

* Increase the current by 2 volts each time and note down how many paperclips have been lifted, so this until you reach 11 volts.

** Increase the number of turns in

Analysis of Experiment

Through this experiment I found out that if you increase the amount of coils in the wire or increase the current then the amount of weight held by the electromagnet will also increase.

When we kept the current constant and increased the number of turns in the coils by 5 then the amount of paperclips being held also increased, although we only managed to lift one or two each time.

When we increased the current by 2 volts each time, the amount of paperclips being held also increased by one more almost on each change.

I noticed that the time where the most amount of paperclips was being held was at the beginning and then end of the experiment, during the middle the amount stayed constant, for example from 10-30 coils, keeping the current constant at 4 volts, the amount of paperclips kept at 3, and also, from 5 volts to 9 volts, keeping the number of turns in the coil constant at 30, the amount of paperclips being held stayed at 3.