Magnetic Effect of Electric Current: Oersted’s Magnetic Revelation

• If the electric current passes through a wire, then the current carrying wire behaves like a magnet.  Hans Christian Oersted (A.D. 1777-1851) was the first person who noticed that every time when the current was passed through the wire the compass needle placed near it got deflected from its usual North-South position.

Magnetic Power: Electromagnets in Action and Practical Uses

• It is a magnet made by passing electric current through it. 
• Electromagnet consists of a coil of insulated wire wrapped around a piece of iron which is magnetised only when an electric current is passed through the coil. 
  • The magnetism of an electromagnet remains as long as the current is flowing in its coil.
• Uses 

• • The electromagnets can be made very strong and can lift very heavy loads. 
  • The electromagnets are also used to separate magnetic material from the junk. 
  • Doctors use tiny electromagnets to take out small pieces of magnetic material that have accidentally fallen in the eye.

Electric Bell: How Electric Bells Ring and Reset?

• Electric bell consists of a coil of wire wound on an iron piece. 
  • The coil acts as an electromagnet.
• Working: An iron strip with a hammer at one end is kept close to the electromagnet. 
  • There is a contact screw near the iron strip. When the iron strip is in contact with the screw, the current flows through the coil which becomes an electromagnet. 
  • It, then, pulls the iron strip and the hammer strikes the gong of the bell to produce a sound. 
  • However, when the electromagnet pulls the iron strip, it also breaks the circuit and the current through the coil stops flowing. 
  • The iron strip comes back to its original position and touches the contact screw again. This completes the circuit. 

• The current flows in the coil and the hammer strikes the gong again. 
• This process is repeated in quick succession.

Conclusion

• Some materials allow the magnetic effect of electric current to pass through them and some resist the flow of current.  
• When an electric current passes through a conductor it shows heating effect, magnetic effect and so on. 
• Electricity is not only limited to power our home appliances. In fact some natural phenomena are visible in our surroundings also.

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