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प्रश्न
What are permanent magnets? Give one example ?
उत्तर
Permanent magnets are those magnets which have high retentivity and coercivity. The magnetization of permanent magnet is not easily destroyed even if it is handled roughly or exposed in stray reverse magnetic fields. For example: steel
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संबंधित प्रश्न
State two advantages of an electromagnet over a permanent magnet.
Write two characteristics of a material used for making permanent magnets ?
Why should the material used for making permanent magnets have high coercivity?
A very long bar magnet is placed with its north pole coinciding with the centre of a circular loop carrying as electric current i. The magnetic field due to the magnet at a point on the periphery of the wire is B. The radius of the loop is a. The force on the wire is
Two long bare magnets are placed with their axes coinciding in such a way that the north pole of the first magnet is 2.0 cm from the south pole of the second. If both the magnets have a pole strength of 10 Am, find the force exerted by one magnet of the other.
The magnetic field at a point, 10 cm away from a magnetic dipole, is found to be `2.0 xx 10^-4 "T"` . Find the magnetic moment of the dipole if the point is (a) in end-on position of the dipole and (b) in broadside-on position of the dipole.
A magnetic needle is free to rotate in a vertical plane which makes an angle of 60° with the magnetic meridian. If the needle stays in a direction making an angle of `tan^-1(2sqrt(3))` with the horizontal, what would be the dip at that place?
A short magnet oscillates in an oscillation magnetometer with a time period of 0.10 s where the earth's horizontal magnetic field is 24 μT. A downward current of 18 A is established in a vertical wire placed 20 cm east of the magnet. Find the new time period.
Assertion: Electromagnetic are made of soft iron.
Reason: Coercivity of soft iron is small.
