# Factors affecting the strength of an electromagnet

Kayleigh Wheeler

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.

Prediction

I think that by increasing the current running through the electromagnet then the more paperclips will be lifted, as I know from my background knowledge, that the more current going through the electromagnet will make it stronger and therefore more weight will be held.

If we decrease the current then the electromagnet will be weaker and will lift less paperclips.

By increasing the amount of coils in the wire and keeping the current at a constant flow, the amount of weight held will increase.

From my background knowledge, I know that this is because more electrical charge ...