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प्रश्न
Why is soft iron used as the core of the electromagnet in an electric bell?
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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. That's why soft iron is used as the core of the electromagnet in an electric bell.
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.
Name one device that uses an electromagnet.
State two advantages of an electromagnet over a permanent magnet.
What is an electroscope? Describe the different stages of charging a gold leaf electroscope negatively with the help of a diagram.
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Reason (R): Wires carrying current in opposite directions repel each other.
Explain the working of the following device.
Speaker
Explain the working of the following device.
Magnetic levitation trains.
