Study the Magnetic Field Pattern of Various Materials Using a Bar Magnet

Materials Required 

  • Drawing board 
  • White sheet  
  • Marker 
  • Molten wax of a candle 
  • Magnet  
  • Magnetic compass 
  • Bars of soft iron, copper, and plastic  

 

The Procedure 

Real Lab Procedure

  • Take a drawing board. 
  • Take the plane white sheet and apply the molten wax on the white sheet and paste it in the drawing board (without any air fillings).
  • Draw two lines perpendicular to each other say NS and EW at the center of the sheet. 
  • Take the magnetic compass and place it in the center of the sheet and rotate the drawing board till the magnetic needle of the compass box exactly overlaps the line NS. 
  • Please note that the needle will point along the north-south direction.  
  • Click to take and place the magnet in the middle of the line NS. 
  • Please note that the axis of the magnet is along the north-south direction and its north pole points towards north. 
  • Take the magnetic compass and map the magnetic field lines using the compass. 
  • Draw the points where horizontal magnetic field of the earth balances the magnetic field of the magnet. These are the neutral points. 
  • Take a bar of soft iron and place it some distance from the magnet.  
  • Map the magnetic field of the magnet using the compass and observe the pattern of the magnetic lines. 
  • Take a bar of copper and place it some distance from the magnet.  
  • Again, Map the magnetic field of the magnet using the compass and observe the pattern of the magnetic lines. 
  • Take a bar of plastic and place it some distance from the magnet. 
  • Now again, map the magnetic field of the magnet using the compass and observe the pattern of the magnetic lines. 

 

Simulator Procedure

  • Drag and drop the Candle on the White sheet.
  • Drag and drop the White sheet on the Drawing board.
  • Drag and drop the Marker on the Drawing board.
  • Click on the Compass.
  • Click on the Drawing board.
  • Click on the Compass.
  • Drag and drop the Magnet on the Drawing board.
  • Click on the Compass.
  • Click on the Marker.
  • Drag and drop the Iron Bar on the Drawing board.
  • Click on the Compass.
  • Click on the Marker.
  • Drag and drop the Copper Bar on the Drawing board.
  • Drag and drop the Plastic Bar on the Drawing board.
  • Click on the Reset button to do the experiment again.

 

Observations

The end of the iron bar where many lines starting from north pole of the magnet enters the iron bar, behaves as the south pole and the other end behaves as the north pole. Thus, the iron bar becomes an induced magnet. Materials which alter the magnetic field lines of magnets are called ferromagnetic materials. You will observe that patterns of magnetic field lines due to a bar magnet are not altered by the presences of copper and plastic bar. These materials do not become induced magnet.