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प्रश्न
State the two properties of the magnetic lines of force around a circular coil.
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उत्तर
The important properties are:
(i) The magnetic lines of force near the wire are nearly circular, especially at the points where
the current enters or leaves the coil.
(ii) At the centre of the coil, the lines of force are almost parallel to each other, showing that the magnetic field at the centre or the coil may be considered uniform.
संबंधित प्रश्न
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.
Tick the most appropriate answer.
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State three uses of an electromagnet?
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.?

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State the energy change that takes’place in a D. C. motor.
