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प्रश्न
The strength of the electromagnet can be increased by
विकल्प
reversing the directions of current
using alternating current of high frequency
increasing the current in the coil
decreasing the number of turns of coil
उत्तर
The strength of the electromagnet can be increased by increasing the current in the coil
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संबंधित प्रश्न
Why is soft iron used as the core of the electromagnet in an electric bell?
Name one device that uses an electromagnet.
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.
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.
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.
