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प्रश्न
How is an electromagnet made? Name two factors on which the strength of magnetic field of the electromagnet depends.
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उत्तर
An electromagnet is made by winding an insulated copper wire around a soft iron core either in the shape of a solenoid or U-shape.
The strength of magnetic field of an electromagnet depends on:
- The number of turns of wire wound around the coil, and
- The amount of current flowing through the wire.
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संबंधित प्रश्न
Why is soft iron used as the core of the electromagnet in an electric bell?
Electromagnets are made up of :
The following figure shows a coil wound around a soft iron bar XY.
- State the polarity at the ends X and Y as the switch is pressed.
- Suggest one way of increasing the strength of electromagnet so formed.
A coil of insulated copper wire is wound around a piece of soft iron and current is passed in the coil from a battery. What name is given to the device so obtained? Give one use of the device mentioned by you.
State two ways through which the strength of an electromagnet can be increased.
Name one device that uses an electromagnet.
State two advantages of an electromagnet over a permanent magnet.
How is the working of an electric bell affected, if alternating current be used instead of direct current?
Unlike magnetic poles ______ whereas like poles ______.
Assertion (A): When 2 long parallel wires, hanging freely are connected in parallel to a battery, they come closer to each other.
Reason (R): Wires carrying current in opposite directions repel each other.
