Procedure :
- Take a white drawing sheet.
- Place a marine compass at the centre of the sheet.
- Draw a line which shows north and south of the earth on the drawing sheet.
- Now remove the compass needle and place a bar magnet at the centre of the sheet showing north of the bar magnet pointing north of the earth.
- Place the magnetic compass near the bar magnet without contact. The needle comes to rest after oscillations.
- Locate end of the pointer with pencil.
Now place the compass needle at this point and once again notice the end of the pointer. - We can repeat the same around the magnet and draw all the points with the help of the pencil.
- We can draw the lines taking the needle too far to the magnet and we can observe the orientation of needle of compass.
- So we can conclude that the strength of field varies with distance from the bar magnet.
- These lines of force are from north of bar magnet to south of the bar magnet.
