## How Electromagnetism Changed our World

written by: sriram balu • edited by: Swagatam • updated: 12/1/2011

Electromagnetism has created a revolution not only in the field of engineering, but also in various other fields like medicine, space, construction etc. Read here to know about various uses of electromagnetism in everyday life from household appliances to research labs.

• slide 1 of 5

### Uses of Electromagnetism in Life

Whatever powered devices we use, from table clocks to microwave ovens, have some form of electromagnetic principle involved in their functioning. It is electromagnetism which has given the flexibility for switching of/on electricity as required.

Electromagnets are created by having an iron core wound with a conductor carrying current. The strength of the electromagnet depends upon the amount of current passing through the conductor. Also the current can be easily stopped and started to form an electromagnet and de-energize respectively as per the need of the work to be performed. This is the principle used for moving heavy objects in the scrap yard. Electricity is connected to the circuit to power the electromagnets when they are energized. Thus the magnets start to attract scrap metal (junk cars), and carry them to the designated area. After locating them in a particular location, the electricity is disconnected from the circuit, thus de-energizing the electromagnet, making the scrap metal detach from the magnet.

• slide 2 of 5

### Uses in Home Appliances:

Many of our electrical home appliances use electromagnetism as a basic principle of working. If we take an example of an electric fan, the motor works on the principle of electromagnetic induction, which keeps it rotating on and on and thus making the blade hub of the fan to rotate, blowing air. Not restricting to fan, many other appliances use electromagnetism as a basic principle. Electric door bell works on this principle too. When the door bell button is put on, the coil gets energized, and due to the electromagnetic forces, the bell sounds. The working of an electric bell is discussed in detailed manner in one of our articles. The loudspeaker which we use for public announcements in meetings, or to transmit message over a long distance, is a perfect example for an electromagnetic appliance. The movement of the coil under the electromagnetic force produces sound which is heard over a very long distance.

Also the modern way of locking the door or a bank safe is to have a magnetic locking device. Either they may be having a number secret code or a magnetic card which when swiped opens the door. The number keys are stored in the magnetic tape on the back of the card, interacts with the magnetic card reader in the door. When the data stored on the card and the memory matches, the door opens. Similar principle is used in the bank’s safe lockers.

• slide 3 of 5

### Uses in Computer Hardware and Memory Storage Devices:

Books are no more required to be carried to schools or colleges. Books, as heavy as hundreds of kilograms can be stored in few milligrams of memory stick. The data are stored in electromagnetic format in the form of bits and bytes. Even the computer hard ware is having a magnetic tape which works on the electromagnetic principle. Not limiting to this, the olden day VCR’s and VCP’s are having huge rolls of magnetic tapes, which had data in it. This can be recorded or read by electromagnetic means only. Also the computer and Televisions use high current electromagnets to produce a beam of electrons from the cathode ray tube. However now a days we use LCD’s and Plasma types.

• slide 4 of 5

### Power Circuits and Communication Devices:

The telephones and mobiles we use to make a call over huge distances could have not taken shape with out electromagnetism. The interaction of the signals and the electromagnetic pulses, make the telephones and mobiles very handy. In power circuits, we use a device called relays, which has the potential to cut down a large current to the load, with the application of small amount of current. A small magnetic coil, which when energized, makes or brakes contact, thus doing a greater amount of work on the other end. Not to forget the usage of electromagnetism in medical field. Everyone must have heard of MRI scans. MRI- is the acronym for Magnetic Resonance Imaging. This sophisticated equipment can scan any minute details in the human body on the principle of electromagnetism.

Modern day fast trains under operation in Japan and Germany are hugely dependant on the electromagnetic principle.

Thus it is evident that the usage of electromagnetism is wide and everywhere. Everyday more and more equipments take birth in the market due to the development in the magnetism and electromagnetic studies.

Few decades ago, only few places on our Planet Earth had the facility to enjoy the electricity and electronic devices. But recent developments led to fast track life style and rapid competitive improvement in every field competing with every country. With the introduction of electricity and electrical devices, electronic devices, and communication equipments, it is possible to reach any part of the world within few hours. Books which weigh several hundred kilograms can be stored in few milligrams of memory stick. These rapid changes started to happen after the introduction and usage of electromagnetism. The above applications are only a few of many more uses of elctromagnetism. It plays a very vital role in our day-to-day life.

• slide 5 of 5

### Sources

www.techsmessaging.com

www.electrocon.net

www.babble.com