Electric and Magnetic Forces
What is magnetism? Magnetism is a force between certain kinds of objects. This force can be either a push or pull. Magnetism can act between two magnets or between a magnet and something magnetic. Objects made of iron, nickel, or cobalt are magnetic.
The two ends of a magnet are different. One end is called the north pole. The other end is called the south pole. Any part of a magnet pulls on things made of iron and a few other metals. Poles that are the same push each other away or repel. Different poles pull toward each other or attract.
Magnets do not have to make contact with another magnet or magnetic object to have its force act on it. The force of the magnet extends beyond the actual poles. Place a paperclip on the table. Test how far from it the magnet can Poles which are be before it causes the paper clip to slide toward the different attract, magnet. Test the strength of two magnets to see how far while poles that are apart they can be before they attract or repel each other. the same repel.
Magnets come in many shapes and sizes. In this image there are bar magnets and circular magnets. There is even a horseshoe magnet. The way a magnet affects other objects depends on how strong it is and how close it is to the other object.
Some magnets are stronger than others. However, the strength of a magnet does not depend on its size. Just because a magnet is big does not mean it is very strong. Some magnets are small and very powerful. Don’t let the size of the magnet fool you!
1 Electric and Magnetic Forces
How are electric forces and magnetism used in the real world? Think about all of the electronic objects or appliances that you use every day. Computers, mobile phones, televisions, microwaves, light bulbs, and hair dryers are a few electronic devices you might have used today. It may not be obvious that electrical devices rely on magnetism. However, it turns out that electricity is directly related to magnetism.
What exactly are magnetism and electric forces, and how are the two related to one another? Let’s take a closer look.
Electricity and Magnetism Many of the devices we use in our homes require motors or generators. These motors take electrical energy and use a magnet to turn that electrical energy into motion. Electromagnets are magnets which are created by using an electric current. Since electricity can be turned on and off, so can an electromagnet. Electromagnets are Think about household items you usually made from wire that is wrapped in use on a daily basis that require coils around an object made of iron. When electricity to function. These items the electromagnet is on, it creates a also depend on magnetism to work magnetic force that can pull on magnetic properly. things. Electromagnets can also be used to power motors, such as those in common household items.
Electromagnets Take a look at how this electromagnet is used to attract paper clips. The more times the wire is wrapped around the nail, the stronger the magnet becomes.
2 Electric and Magnetic Forces
Do your clothes cling together as they come out of the dryer? Do they crackle as you pull them apart? Perhaps you walked across a room in your socks and were shocked when you touched a doorknob. Maybe you have even shocked another person! Have you experienced fly-away hair?
All of these are examples of static electricity. Static electricity is an electrical charge that builds up as items rub against each other. The negative charges build up and want to jump away from each other. When you touch the doorknob or another person, you feel, hear, and sometimes even see the electrical charge jump. The negative charge is so strong that the items do not need to make contact for the electrical charge to make the jump.
The form of static electricity that you probably know best is lightning. The clouds rubbing together cause different charges to build up inside them. When the negative charges build up, they want to jump to areas with positive charges. You can see the lightning and hear the thunder as the electrical charge is released.
You see cloud-to-ground lightning in this picture. There is also ground-to-cloud lightning and cloud-to-cloud lightning.