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प्रश्न
State two advantages of an electromagnet over a permanent magnet.
उत्तर
- An electromagnet can produce a strong magnetic field.
- The strength of the magnetic field of an electromagnet can easily be changed by changing the current in its solenoid.
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संबंधित प्रश्न
Why is the core of an electromagnet made of ferromagnetic materials?
Why should the material used for making permanent magnets have high coercivity?
If the current is doubled, the deflection is also doubled in
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The desirable properties for making permanent magnets are _________________ .
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The magnetometer of the previous problem is used with the same magnet in Tan-B position. Where should the magnet be placed to produce a 37° deflection of the needle?
A short magnet makes 40 oscillations per minute when used in an oscillation magnetometer at a place where the earth's horizontal magnetic field is 25 μT. Another short magnet of magnetic moment 1.6 A m2 is placed 20 cm east of the oscillating magnet. Find the new frequency of oscillation if the magnet has its north pole (a) towards north and (b) towards south.
Assertion: Electromagnetic are made of soft iron.
Reason: Coercivity of soft iron is small.
