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प्रश्न
Describe a simple Experiment to demonstrate that there Exists a magnetic field around a current-carrying conductor.
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उत्तर
The conductor is kept in N-S direction and its ends are connected to a battery, rheostat and a tapping key. When the key is open i.e., no current flows in the conductor, the needle points in N-S direction. As the key is pressed and a current passes in the conductor, the needle deflects. This shows that a magnetic field Exists around a current carrying conductor.
संबंधित प्रश्न
State two ways of magnetising an iron piece?
Suppose you are given a long bar magnet and you are asked to break it into four small magnets. Draw diagrams showing the polarities of each broken part.
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.
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.
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.
Electric bell ______.
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 is dynomo (a.c. generator)? State the principle on which it works.
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
