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प्रश्न
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 ______.
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उत्तर
Electromagnet core- soft iron
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संबंधित प्रश्न
Name the type of transformer shown in fig . What changes will you observe regarding the brightness of the lamp, if
(a) The no. of turns in the secondary is doubled?
(b) The part X of the transformer is removed?
( c) The core of the transformer is made out of copper?
(d ) The A.C. supply is replaced by D.C.?
Complete the following sentence :
On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
State the purpose of the iron core.
How does a magnetic field set up by a solenoid change when number of turns are increased?
State the condition when an electric charge can give rise to a magnetic field.
State two advantages of an electromagnet over a bar magnet.
State three factors which govern the speed of rotation of an electric motor.
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting an the coil is maximum.
What is dynomo (a.c. generator)? State the principle on which it works.
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?
