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प्रश्न
State two advantages of an electromagnet over a permanent magnet.
उत्तर
- An electromagnet can produce a strong magnetic field.
- The strength of the magnetic field of an electromagnet can easily be changed by changing the current in its solenoid.
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संबंधित प्रश्न
The strength of the electromagnet can be increased by
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.
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?
How is the working of an electric bell affected, if alternating current be used instead of direct current?
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.
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.
