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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.
उत्तर
Soft iron is used in all.
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संबंधित प्रश्न
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 differences between an electromagnet and a permanent magnet.
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.?
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.
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On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
State two factors on which the magnitude of an induced e.m.f. in the secondary coils of a transformer depends.
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?
State important properties (or characteristics) of magnetic lines of force around a straight conductor.
