# Magnets and Coils

How do they work?

How does the number of coils affect electromagnetism?

Hypothesis: When there is a flow of moving electrons, a magnetic field is created. We use the equation F = NIlB (Force = Number of coils x Current x Length of Wire x Magnetic Field Strength) to work out the magnetic force produced in a wire when there is an electric current present. Using this equation we can see that increasing the length of the wire (amount of coils) gives a larger force. So increasing the amount of coils in an electromagnet gives a larger EMF. Variables-

Independent: Length of wire, Number of Coils in magnet

Dependent: EMF produced, Magnetic Field Strength, amount of coils in magnet. Control: Volts, Amps, Ruler.

AIM – To find out how the number of coils affects the magnetism of an electromagnet. BACKGROUND –

Electromagnets use a fundamental force of physics, the electromagnetic force. Along with gravity and the strong and weak interactions (forces), the electromagnetic force is one of the four basic forces in the universe force. When a charged particle moves, it creates a magnetic field around its path of travel. This magnetic field moves with the charged particle along its path. This magnetic field is one of the key components of the equation F = NIlB, arguably the most important equation involving electromagnetism. B stands for the Magnetic Field Strength, so using a bit of common sense you can see that changing B will change the overall EMF (electromagnetic force). I will Explain I and l in a minute (that’s L) We usually move electrons to do work, and when we move a lot of them, we create a large magnetic field around the conductor through which the electrons move. The moving electrons are electricity, and if we coil the conductor through which the current is flowing, we can cause the magnetic field around the individual wires to "add up" and make one bigger field. The bigger field "reaches around" the entire coil of wire, and the magnetic lines of...

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