## Tuesday, November 20, 2012

### A cool ELECTROMAGNET experiment I've done

Science experiment: Building an electromagnet
Things I need: 19 cm nail, 3 in copper wire, 6 volt battery, compass
Steps I took:
Step 1: Some of the copper wire needs to be exposed so that the battery can make a good electrical connection. Use a pair of wire strippers to remove a few centimeters of insulation from each end of the wire.
Step 2: Neatly wrap the wire around the nail. The more wire you wrap around the nail, the stronger your electromagnet will be. Make sure that you leave enough of the wire unwound so that you can attach it to the battery. When you wrap the wire around the nail, make sure that you wrap the wire all in one direction. You need to do this because
the direction of a magnet field depends on the direction of the electric current creating it.

Step 3: Attach one end of the wire to the positive terminal of the battery and the other end of the wire to the negative terminal of the battery. If all has gone well, the electromagnet should be working.
To test this theory, I pointed the magnetized nail near the compass and the needle facing south pointed towards it.
An electromagnet is a magnet that runs on electricity. Unlike a permanent magnet, the strength of an electromagnet can easily be changed by changing the amount of electric current that flows through it. The electromagnet was developed from a series of observations. In 1820 Hans Christian Oersted discovered the relationship between electricity and magnetism. He found out that the wire carrying a current had a magnetic field which acted like a magnet. Electromagnetism is very important in our lives. The main technological uses of electromagnets are in storing information and moving things. They are used in many electrical devices like electrical balls (Ex. Plasma flashers), loudspeakers, magnetic locks and various magnetic recording devices such as computer disks, tape recorders, VCR, etc. Televisions also use electromagnets to power the cathode ray tube to regulate the direction of the beam of electrons, used to illuminate the screen. Electromagnets are also used in telephones, mobile phones and doorbells. Moving metals and picking up cars in junkyards are some of the common everyday uses of electromagnets. Spacecrafts also use electromagnets in the propulsion system to generate power.

#### 1 comment:

1. I read your post which was really good waiting for next post
ELECTROMAGNET