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प्रश्न
How do you account for the following fact?
Soft iron keepers help to prevent the magnets from losing their magnetic properties.
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उत्तर
In magnets, external fields like earth’s magnetic field can randomize the domains. Perhaps stray fields caused by flowing currents in nearby electric circuits can also disturb i the alignment of domains lying inside a magnet. Given enough time, such magnets may find their domains randomly oriented and hence their net magnetisation may get lost. A keeper for magnets is just a strong permanent magnet that keeps all the domains pointing the same way and realign those that may have gone astray and hence magnet, can retain its magnetism for a long time.
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संबंधित प्रश्न
What are the two ways in which you can trace the magnetic field pattern of a bar magnet?
The magnetic field lines produced by a bar magnet:
(a) originate from the south pole and end at its north pole
(b) originate from the north pole and end at its east pole
(c) originate from the north pole and end at its south pole
(d) originate from the south pole and end at its west pole
What is a natural magnet? State two limitations of a natural magnet.
Explain what you understand by magnetic induction. What role does it play in attraction of a piece of iron by a magnet?
Figure. shows a bar magnet placed on the table top with its north pole pointing towards south. The arrow shows the north-south direction. There are no other magnets or magnetic materials nearby.
Indicate by crosses, the likely positions of the neutral points.
The intensity of a magnetic field is indicated by the lines of ______.
Select the correct option:
The magnetic strength of a bar magnet is:
A wire 10 cm long carrying a current of 1.5 A is held in a uniform magneÑic field in which B = 10-3 T. Calculate the force on the wire if it is held perpendicular to the lines of the magnetic field.
A student fixes a white sheet of paper on a drawing board. He places a bar magnet in the centre and sprinkles some iron filings uniformly around the bar magnet. Then he taps gently and observes that iron filings arrange themselves in a certain pattern.
- Why do iron filings arrange themselves in a particular pattern?
- Which physical quantity is indicated by the pattern of field lines around the bar magnet?
- State any two properties of magnetic field lines.
State the inference drawn about the direction of the magnetic field lines on the basis of the following diagrams.
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| Figure 'a' | Figure 'b' |
