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प्रश्न
Name the material of core in (a) an electric bell, (b) electromagnet, (c) a d.c. motor, (d) an a.c. generator and (e) a transformer.
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उत्तर
Soft iron is used in all.
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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?
Name two factors on which the strength of magnetic field of an electromagnet depends and state how does it depend on the factors stated by you.
State two differences between an electromagnet and a permanent magnet.
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electromagnet ______.
Complete the following sentence :
On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
The magnetic flux through a coil having 100 turns decreases from 5 milli weber to zero in 5 second. Calculate the e.m.f. induced in the coil.
What will be the effect on the working of an electric bell if instead of a direct current an alternating current is used?
What energy conversion takes place during the working 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?
Which magnet will you use?
Iron is to be separated from trash.
