If Electric current is passed in a simple magnet wound with the coil of insulated wire and the magnetic field is produced the magnet formed by this process is called Electromagnet. The core of the magnet which is wound with the wire is made of ferromagnetic or ferromagnetic materials such as iron.
The magnetic field can be quickly changed by changing the amount of electric current passing in the insulated coil, and when the electric current is turned off, the magnetic field disappears. This means that the strength of the magnetic field in an electromagnet is directly proportional to the electric current passing through it.
Electromagnets are used in electric devices like generators, motors, relays, etc. and also in the MRI machine, hard disks and other scientific instruments.
The phenomenon by which magnetism is produced by the effect of electric current is called Electromagnetism. Danish physicist Hans Christain Oerstud discovered the phenomenon of Electromagnetism in 1819.
Magnetic Effect of Electric Current
When an electric current is passed through a conductor, the magnetic lines of force are set up around it.
Let us understand the magnetic effect of electric current with the help of an example given below
Take a hard board and sprinkle some iron filling on it and tap it slightly. Now when electric current is passed through it, it is analyzed that
- The magnetic field varies accordingly; that means it changes when it is near, and when it is at a certain distance from the conductor. It is stronger when it is close to the conductor and becomes weaker as the distance increases from the conductor.
- Larger the density of the current stronger will be the magnetic field this means that the strength of the magnetic field around the conductor depends upon the magnitude of flow of electric current.
- The direction of flow of current is perpendicular to the direction of the magnetic field.
- If the current direction is reversed, then the direction of the magnetic field is also reversed, and this can be seen by placing the magnetic needle near the conductor.
Applications of Electromagnets
- Electromagnets are widely used for storing the information and moving things.
- They are used in many electrical devices like loud speakers, electric bells, magnetic locks and also in magnetic recording devices like tape recorders, computer disks, etc.
- In television (CRT tubes), telephones, door bells and mobiles
- Electromagnets are also used in recycling plants for the purpose of garbage dumping.
- Used in the propulsion system in spacecraft to generate power.