Shu Vidyut Sachit Teukay Che

SR No.: 005303
Original Sutra Author: N/A
Author: Mahendramuni
Publisher: Anekant Bharati Prakashan
Publication Year: 2005
Total Pages: 312
Language: Gujarati
Classification: Book_Gujarati
File Size: 13 MB

Page 122

(b)
2. The induced e.m.f. lasts as long as the change in the
magnetic flux continues. 3. The magnititude of the induced e.m.f. is directly propor
tional to the rate of change of the magnetic flux linked
with the circuit. Text-book of Physics, op.cit. pp 39 to 52— "Electromagnetic Induction and Faraday's Experiments A scientist named Michel Faraday discovered in the year 1831 that a change in the value of the magnetic flux linked with a conducting coil gives rise to induction of an electromotive force in the coil. The emf generated this way is called the induced e.m.f. When the bar magnet is near the coil, some of the magnetic lines of force are passing through the coil; that is some magnetic flux is linked with the coil'. Now when there is relative motion between the coil and the magnet, the amount of flux linked with the coil is changing. When the relative motion stops, there is no further change in the amount of the flux linked. So we conclude that, "when there is a change in the flux linked with the coil, there is an emf generated in the coil.” The observation that a faster motion of the magnet gives rise to a larger deflection shows that the emf generated depends upon the rate of change of the flux linking the coil. The current resulting from this "induced emf.” is called the “induced current”. When a Current flows in a coil, magnetic flux is produced due to this current and the coil now acts as a magnet. Which face of the coil acts like a north pole and which face becomes a south pole depends upon the direction of the current in the coil. Thus, we see that the direction of the induced current and the corresponding direction of the resulting magnetic field is a consequence of the conservation of energy. This leads us to Lenz's law which states : "If an agency generates an induced emf through its action (such as motion of the magnet as illustrated) the induced emf would be such that the current produced by this emf would generate a magnetic field such as to oppose the action of the agency." 3. Faraday's Law Faraday gave the law relating the induced emf in a circuit with the rate of change of the flux.
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