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प्रश्न
Name one device that uses an electromagnet.
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उत्तर
Electric bell
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संबंधित प्रश्न
Electromagnets are made up of :
The strength of the electromagnet can be increased by
You are required to make an electromagnet from a soft iron bar by using a cell, an insulated coil of copper wire and a switch.
- Draw a circuit diagram to represent the process.
- Label the poles of the electromagnet.
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.
State two differences between an electromagnet and a permanent magnet.
Name the material used for making the armature of an electric bell. Give a reason for your answer.
Explain, why steel is used in preference to soft iron for making permanent magnets while soft iron is used in preference to steel for making electromagnets.
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.
Explain the working of the following device.
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