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Explain Why, an Electromagnet is Called a Temporary Magnet. - Science

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प्रश्न

 Explain why, an electromagnet is called a temporary magnet.

उत्तर

 An electromagnet is called a temporary magnet because its magnetism stays only for the duration of current passing through it. All the magnetism disappears as soon as the current is switched off. 

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पाठ 2: Magnetic Effects of Electric Current - Exercise 2 [पृष्ठ ८२]

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लखमीर सिंह Physics (Science) [English] Class 10
पाठ 2 Magnetic Effects of Electric Current
Exercise 2 | Q 23.2 | पृष्ठ ८२

संबंधित प्रश्‍न

The magnetic flux through a loop is varying according to a relation `phi = 6t^2 + 7t + 1` where `phi` is in milliweber and t is in second. What is the e.m.f. induced in the loop at t = 2 second?


A conducting square loop of side l and resistance R moves in its plane with a uniform velocity v perpendicular to one of its sides. A uniform and constant magnetic field Bexists along the perpendicular to the plane of the loop as shown in figure. The current induced in the loop is _____________ .


Fig. shows a simple form of an A.C. generator.

(a) Name the parts labeled A and B.
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(c) Which of the output terminals is positive if the coil is rotating in the
direction shown in the diagram (anticlockwise)?
( d ) What is the position of the rotating coil when p.d. across its ends is zero? Explain why p.d. is zero when the coil is at this position .
(e) Sketch a graph showing how the p.d. across the ends of the rotating coil varies with time for an A.C. dynamo.
( f) On th e same sheet of paper and vertically below the first graph using the same time scale, sketch graphs to show the effect of
(i) Doubling the speed of rotation and at the same time keeping
the field and the number of turns constant,
(ii ) Doubling the number of turns on the coil and at the same time
doubling the speed of rotation of the coil, keeping th e speed
constant.


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Induced current flows through a coil ______.


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