Electromagnetism

Edited by Jamie (ScienceAid Editor), Administrator, Taylor (ScienceAid Editor)

Electric Motor

When an electric current passes at a right angle to a magnetic field, a force is produced, which moves perpendicular to the magnetic field. Have a look at the diagram below to help you understand this.

Was this helpful? Yes | No | I need help

flemming's left hand rule

Put your Index finger in the direction of the current; Middle finger in the direction of the magnetic field; and point your thumb up and it should point in the direction of the force.

This phenomenon can be used to produce a rotation in what is called a simple DC motor. This principle is also applied to make dynamos, which are used to generate electricity; this is explained below.

Ad

Electromagnetic Basics

A voltage is created in a conductor when it is moved through a magnetic field. So moving a magnet through a coil of wire produces the same effect. The size of this voltage can be increased by:

  1. 1
    Increasing the number of turns on the coil.
    Advertisement
    Was this step helpful? Yes | No | I need help

  2. 2
    Increasing the speed of the magnet.
    Was this step helpful? Yes | No | I need help

  3. 3
    Increasing the strength of the magnetic field.
    Was this step helpful? Yes | No | I need help

    Advertisement

This effect may seem boring and useless, but because this process is used to generate electricity, and you wouldn't be able to read this on your computer right now - without it.

Transformers

how a transformer works

The above diagram shows a step up transformer because it increases the voltage. Step up and step down transformers are used all over the country for your domestic electricity supply. They change the voltage up and down for the different stages of its transportation: increasing from the power plant to electric cables, decreasing from cables to your home. Your stereo has a step up transformer. When you turn up the volume, it increases the voltage. The secondary voltage is 'more' than the initial. When the secondary voltage is 'less' than the initial, it's called a step down transformer. An example would be fluorescent lights - as it requires more power to turn them on, than to run them.

Was this helpful? Yes | No | I need help

There is a relationship between the primary (in) and secondary (out) voltages on the transformer depending on the number of turns the wire takes around the magnet.

transformer equation

Comments

ScienceAid welcomes all comments. If you do not want to be anonymous, register or log in. It is free.




Jamie
Featured Author
166 Articles Started
1,267 Article Edits
42,900 Points
Jamie is a featured author with ScienceAid. Jamie has achieved the level of "Captain" with 42,900 points. Jamie has started 166 articles (including this one) and has also made 1,267 article edits. 8,700 people have read Jamie's article contributions.
Jamie's Message Board
Jamie: Hi, my name is Jamie.
Jamie: Can I help you with your problem about "Electromagnetism"?
 

Article Info

Categories : Electricity

Recent edits by: Administrator, Jamie (ScienceAid Editor)

Share this Article:

Thanks to all authors for creating a page that has been read 7 times.

Do you have a question not answered in this article?
Click here to ask one of the writers of this article
x

Thank Our Volunteer Authors.

Would you like to give back to the community by fixing a spelling mistake? Yes | No