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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
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उत्तर
The strength of the electromagnet can be increased by increasing the current in the coil
APPEARS IN
संबंधित प्रश्न
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.
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.
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 advantages of an electromagnet over a permanent magnet.
Why is soft iron used as the core of the electromagnet in an electric bell?
Name the material used for making the armature of an electric bell. Give a reason for your answer.
What is an electroscope? Describe the different stages of charging a gold leaf electroscope negatively with the help of a diagram.
Explain the working of the following device.
Speaker
Explain the working of the following device.
Magnetic levitation trains.
