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प्रश्न
There are two knitting needles. One of them is magnetized. How will you find out which one is magnetized, if no other magnet is available?
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उत्तर
When an iron bar is magnetized, it slightly increases in length due to the setting of molecular magnets along straight chains. So, on precisely measuring the length of the knitting needle, the knitting needle which is slightly longer in length than the other is magnetized.
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संबंधित प्रश्न
Match the following
| Column A | Column B |
| (a). Human body | (1). electric bell |
| (b). Silk thread | (2). current |
| (c). Charge in motion | (3). conductor |
| (d). soft iron | (4). electromagnet |
| (e) . Electromagnet | (5). insulator |
Select the correct answer
An example of natural magnet is
Answer the following.
Why is it not possible to isolate a single magnetic pole?
How will you do this?
Determine whether a material is magnetic or non-magnetic.
Since every iron atom is a tiny magnet, why are not all iron bar magnets?
Give scientific reason:
Not attraction but repulsion is a sure test of magnetism.
Distinguish between
Natural and artificial magnets.
Artificial magnets are made in different shapes such as ______, _____ and _______.
One of the following is an example for a permanent magnet.
Match the following:
| 1. | Electricity and magnetism | a. | Step-down transformer |
| 2. | Force on the conductor | b. | Hans Christian Oersted |
| 3. | Electric bell | c. | I LB |
| 4. | Ns <Np | d. | Electromagnet |
