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प्रश्न
How is the working of an electric bell affected, if alternating current be used instead of direct current?
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उत्तर
If an A.C. source is used in place of a battery, the core of the electromagnet will get magnetized, but the polarity at its ends will change. Since the attraction of the armature does not depend on the polarity of the electromagnet, the bell will still ring on pressing the switch.
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संबंधित प्रश्न
Why is soft iron used as the core of the electromagnet in an electric bell?
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.
Electromagnets are made up of :
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.
Name one device that uses an electromagnet.
State two differences between an electromagnet and a permanent magnet.
Why is soft iron used as the core of the electromagnet in an electric bell?
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.
What is an electroscope? Describe the different stages of charging a gold leaf electroscope negatively with the help of a diagram.
Explain in detail the application of 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.
Speaker
Explain the working of the following device.
Magnetic levitation trains.
