Extramarks-background-image

•    A magnet attracts the small pieces of iron.
•    A freely suspended bar magnet, always rests in north south direction.
•    A magnet has two poles north pole and South Pole.
•    These poles exist in pair.
•    Like poles repel each other, while unlike poles attract each other.
•    A magnetic compass is a small magnetic needle pivoted at its Centre so as to rotate freely.
•    It is used to indicate the north-south direction at a place.
•    Repulsion is a sure test of a magnet.
•    The space around the magnet in which the magnetic needle of the magnetic compass gets influenced is called the magnetic field of that magnet.


                                                        

•    Electromagnet is a temporary magnet which is made up of soft iron by the electrical method.
•    An electromagnet acquires magnetism so long as current flows in the coil wound around a cylindrical tube. The strength of magnetic field of an electromagnet increases by three ways:

  1. By increasing the number of turns in the coil.
  2. By increasing the intensity of current in the coil.
  3. By inserting a soft iron core in the coil.

•    The electromagnets are mainly used:

  • To separate the iron from other substances
  • To lift big pieces of iron scrap, girders, plates etc.
  • To separate iron dust from wounds
  • To load furnace with iron
  • To obtain magnetic field in the electrical gadgets like electric bell, electric motor etc.

 

Download App

Download Extramarks – The Learning App

Take your CBSE board preparation to another level with AI based and rich media animation on Extramarks - The Learning App.

Features of Learning App

  • Learn with studybot “Alex”
  • Personalized Learning journey
  • Unlimited doubt Solving
  • Quiz, challenge friends
  • Leaderboard Ranking
  • Academic Guru

Download App Download App