Motional EMF
INTRODUCTION
When a conductor moves through a magnetic field, it generates an electric field. This electric field can then cause the conductor to conduct current, which produces power.The fundamental ideas in the study of electromagnetism that have a wide variety of real-world applications are motional emf and induced current.Applications include transformers, sensors, eddy current brakes, magnetic levitation, electric motors, generators, and electric motors.These ideas are fundamental to the design and optimisation of a variety of magnetic devices that result in effective and sustainable energy solutions.The principles of motional emf, induced current, and power usage will be discussed in this article.
MOTIONAL EMF
The emf actuated across the closures of a conductor because of its movement in a magnetic field is called motional emf.
DESCRIPTION:
Conductor PQ of length L is allowed to continue on a U-moulded leading rails. (Here the slidable conductor PQ is moved outwards with a speed v).When the conductor moved outwards the space of the rectangular circle increments and consequently the attractive transition connected with the shut circle increments. Thus,the magnetic flux linked with the closed-loop increases.
An emf is set up across the conductor PQ due to which an initiated current stream in the anticlockwise course (as displayed in the image).According to Faraday’s law of electromagnetic induction the emf incited is – BLv
MAGNETIC FLUX LINKED WITH THE CLOSED-LOOP
INDUCED EMF :
INDUCED CURRENT
LENZ’S LAW
Lenz’s law expresses that, ” The direction of the actuated current in a circuit is with the end goal that it goes against the reason which produces it”.
POWER USED
RIGHT HAND PALM RULE
FLEMING’S RIGHT HAND RULE
WHAT IS A SOLENOID? DERIVE AN EXPRESSION FOR THE MAGNETIC FIELD INSIDE A SOLENOID.
SOLENOID:
Solenoids are basically electromagnets, they are made of a big coil of wire wound in the form of helical coils, When the current flows through the coil, magnetic field is generated in it, The magnetic field is strong along the axial line of the solenoid. The core in the center is made from a ferromagnetic material.
EXPRESSION FOR MAGNETIC FIELD INSIDE A SOLENOID :
The amperean loop in the following image is the rectangular closed path abcd which is under consideration. Here ab = cd = l is the length of the rectangle. At various turns of the coil current comes out of the plane of the screen/paper which are marked as dot. At various turns of the coil current enters the plane of the screen/paper, which are marked as cross.
| THE MAGNETIC FIELD INSIDE A CLOSELY WOUND LONG SOLENOID IS UNIFORM EVERYWHERE BUT ZERO OUTSIDE THE COIL. |
AMPERE CIRCUITAL LAW :
APPLYING AMPERE CIRCUITAL LAW:
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