Page 3 - HA

 Mention at least four properties of magnetic field lines.

 Why two magnetic field lines cannot intersect with each other?

 Poles are not marked in a bar magnet. How will you find out its poles?

 You are provided with two identical metal bars. One out of the two is a magnet.

Suggest two ways to identify the magnet.

Activity---1

To represent magnetic field lines around a bar magnet using iron fillings.

Materials Required:

 Bar magnet
 Iron fillings

 Drawing board

Observation:

When iron filings are spread over the magnets, you can see the outline of the magnetic force
or the magnetic field. When the iron filings are sprinkled, those very close to
the magnet, where the magnetic force is the strongest, will cling to the magnet.
Those filings a little farther away, where the magnetic force is less strong, will align
themselves with the magnetic flux lines, but they will not be drawn to cling to
the magnet.

Explanation:

Iron fillings get stuck to a magnet because iron is attracted towards magnet. When
an iron filling finds itself in a magnetic field it becomes magnetised. Then it attracts
towards magnet mostly at the poles because magnetic field is so powerful at the poles

of magnet. The feild lines are more near the poles so feild is denser so force is more.

Inference: