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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.
APPEARS IN
संबंधित प्रश्न
State whether the following statement is true of false:
The axis of earth's imaginary magnet and the geographical axis coincide with each other.
Define magnetic field lines. Describe an activity to draw a magnetic field line outside a bar magnet from one pole to another pole.
What is a natural magnet? State two limitations of a natural magnet.
In following figure, draw at least two magnetic field lines between the two magnets.
(b) 
Complete the following sentence :
If the field lines in a magnetic field are parallel and equidistant, the magnetic field is __________ .
Draw diagram showing the arrangement of the lines of force for a piece of soft iron laid in line with the magnetic field.
State whether true or false. If false, correct the statement.
Magnetic field lines always repel each other and do not intersect.
Inside the magnet, the field lines moves ____________.
Magnetic field lines determine ______.
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.
