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प्रश्न
Point out three differences between an electromagnet and a bar (or permanent) magnet.
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उत्तर
| Electromagnet | Bar Magnet |
| 1. An electromagnet exhibits a much stronger magnetic field. | A bar magnet is not able to exhibit a strong magnetic field. |
| 2. Its polarity can be reversed by reversing the direction of current flowing in the turns of the coil (or solenoid). | Its polarity is fixed. |
| 3. It is a temporary magnet, it behaves as a magnet only when the current flows through the solenoid. | It is a permanent magnet and cannot be readily demagnetized. |
संबंधित प्रश्न
How will you make an iron bar electromagnet? Draw a diagram showing the polarities of the electromagnet?
State three uses of an electromagnet?
What is an electric motor?
Name the material of core in (a) an electric bell, (b) electromagnet, (c) a d.c. motor, (d) an a.c. generator and (e) a transformer.
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electromagnet ______.
The magnetic flux through a coil having 100 turns decreases from 5 milli weber to zero in 5 second. Calculate the e.m.f. induced in the coil.
State two advantages of an electromagnet over a bar magnet.
State the energy change that takes’place in a D. C. motor.
A current-carrying solenoid is suspended so as to freely rotate in a horizontal plane. State in what direction will it rest. Give a reason for your answer.
or
When a solenoid that is carrying current is freely suspended, it comes to rest in a particular direction. Why does this happen?
What are the factors that govern the magnitude of force acting on a current carrying conductor which is freely suspended in a magnetic field?
