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प्रश्न
Why is soft iron used as the core of the electromagnet in an electric bell?
उत्तर
The soft iron bar acquires the magnetic properties only when an electric current flows through the solenoid and loses the magnetic properties as the current is switched off. Hence, soft iron is used as the core of the electromagnet in an electric bell.
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संबंधित प्रश्न
The incomplete diagram of an electric bell is given in Figure. Draw winding of coil on the core and complete the electric circuit in the diagram.
G-Gong, H-Hammer, A-Armature, C-Core, B-Battery.
Name one device that uses an electromagnet.
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Name the material used for preparing an electromagnet.
How is an electromagnet made? Name two factors on which the strength of magnetic field of the electromagnet depends.
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.
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- 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.
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Show with the aid of a diagram how a wire is wound on a U-shaped piece of soft iron in order to make it an electromagnet. Complete the circuit diagram and label the poles of the electromagnet.
State two ways through which the strength of an electromagnet can be increased.
Name one device that uses an electromagnet.
State two differences between an electromagnet and a permanent magnet.
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Unlike magnetic poles ______ whereas like poles ______.
Explain the working of the following device.
Magnetic levitation trains.
