Advertisements
Advertisements
Question
Explain with the help of a diagram how the intensity and direction of the magnetic field of a bar magnet can be determined.
Advertisements
Solution
Take drawing cardboard and sprinkle some iron filings on it. Notice the position of the iron filings as a whole. Now, take a bar magnet and slowly bring it below the cardboard. You will observe that the iron filings tend to attract towards the magnet as shown below.
To find the direction of the magnetic field around a bar magnet, place a magnetic compass with its South-Pole near one of the poles of the bar magnet. Locate the point where the North-pole of the needle points. Now, lift the needle and place its South-Pole on the marked point. Now, again see where the North Pole points. Repeat this process and you will get the direction of the magnetic field as shown below.
To find the intensity of the magnetic field around a region of a bar magnet, we need to calculate the number of lines crossing through the unit area of that region. For example, if we have to calculate the intensity of the magnetic field at points A and B, then draw unit areas around A and B first and then calculate the number of lines passing through that area. By doing so, we see that the intensity of the field at A is greater than that at B.
RELATED QUESTIONS
Where do the manufactures use a magnetic strip in the refrigerator? Why is this magnetic strip used?
A plotting compass is placed near the south pole of a bar magnet. The pointer of plotting compass will:
- The diagram shows a bar magnet surrounded by four plotting compasses. Copy the diagram and mark in it the direction of the compass needle for each of the cases B, C and D.
- Which is the north pole, X or Y?
Describe an experiment to show that the maximum attractive property is at the poles of a magnet?
The change in magnetic field lines in a coil is the cause of induced electric current in it. Name the underlying phenomenon.
Define magnetic field.
Explain why the ozone layer is not affected by solar wind.
The magnetic field is a quantity that has magnitude only.
Assertion (A): The work done by a magnetic field on a moving charge is zero.
Reason (R): In a magnetic field force is perpendicular to the velocity.
A wire placed along north south direction carries a current of 5A from south to north. Find the magnetic field due to a 1m piece of wire at a point 200 cm north east from the piece.
