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प्रश्न
What is an electromagnet?
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उत्तर
An electromagnet is a temporary strong magnet made from a piece of soft iron when current flows in the coil wound around it. It is an artificial magnet.
संबंधित प्रश्न
The diagram shows a coil wound around a U shape soft iron bar AB.
1) What is the polarity induced at the ends A and B when the switch is pressed?
2) Suggest one way to strengthen the magnetic field in the electromagnet
3) What will be the polarities at A & B if the direction of current is reversed in the circuit?
You are given an iron nail, a torch cell, and a long piece of insulated copper wire. With the help of a labelled neat diagram, describe in steps how you will make the nail, an electromagnet.
State three uses of an electromagnet?
What is an electric motor?
State two factors on which the magnitude of an induced e.m.f. in the secondary coils of a transformer depends.
State two factors on which the strength of induced e. m.f. depends.
Describe briefly one way of producing an induced current in a coil. State one factor that determines the magnitude of induced e.m.f.
How does a magnetic field set up by a solenoid change when a soft iron core is inserted inside solenoid?
State the principle of a D. C. motor.
A current-carrying solenoid is suspended so as to freely rotate in a horizontal plane. State in what direction will it rest. Give a reason for your answer.
or
When a solenoid that is carrying current is freely suspended, it comes to rest in a particular direction. Why does this happen?
