What is 1 Weber? What is 1 Tesla.

After watching this video you will be able to define 1 Weber and 1 Tesla.

What is 1 weber?

Weber is an unit of magnetic flux. And also, for magnetic pole strength. It is named after famous German Physicist, Wilhelm Eduard Weber.

In this tutorial, we shall define 1 weber, by using Faraday's law of electromagnetic induction. Which says, if you move an electric loop, near a magnet, then an electromotive force, or electric potential, will be generated, throughout the loop. You may detect the instantaneous potential difference by a voltmeter, attached to it. The incidence is known, as electromagnetic induction. The reason behind this induction, is the changes in magnetic flux, through the loop. When the loop moves, the number of field lines, passed through it, changes. Hence, an electromotive force generated in the loop. But, when it stops, no change occurs. And therefore, the voltmeter shows, a null reading.

At a distant point from the magnet, where, movements of the loop, do not produce any electromotive force, is called a zero flux region. And, the surface may be termed, as a 0 Weber surface. Now, move the loop towards the magnet, at some uniform velocity. See, there is an electromotive force.

Take a slow motion. Now, suppose, after a time span of 1 second, the loop reaches that point. And, the voltmeter reading shows, a 1 volt potential difference. Then the magnetic flux, attached to this loop area, is called, 1 weber. If you move the loop faster, the voltmeter may show, a 2 volt reading, after 1 second, then the magnetic flux through that surface, is 2 weber. A 3 weber, 4 weber can also be shown in this way. Remember, the loop in this case is a single turn one, not multi turn.

So, What we learn from this? 1 weber is the amount of magnetic flux, attached to a single turn loop, when the loop approaches a magnet, in 1 second, from a zero flux zone, to induce a 1 volt electromotive force in it.

Magnetic flux and magnetic fields are invisible. Magnetic flux are typically described, as some imaginary magnetic field lines. When, these lines pass perpendicularly through a surface. Then, it is called, the magnetic flux, through the surface. More field lines indicates more flux, or more weber. If you move a surface about a magnetic field, the value of the magnetic flux may change. Again, if you increase the surface area, the flux value should be higher. Magnetic flux depends on the area of the surface. More surface area means more weber. When, you measure flux value through a surface , of exactly 1 square meter, then it is expressed in tesla.
When a magnetic flux, of amount 1 weber, pass perpendicularly, through a surface of area, exactly 1 square meter. Then, the magnetic field, at this location, is called 1 tesla. The unit, Weber, is used to describe the total magnetic flux, through a surface of any size. The surface may be either large, or small. But, tesla defines the magnetic flux, at some specific location, through a unit surface area. More tesla means more powerful magnetic field. Weber does not give any idea, about the strength of a field.

If you cover a magnetic pole, by some imaginary closed surface. Then, you might be able to find out the total flux, emitted from the pole. It is called, the magnetic pole strength, of the magnet. And, S I unit of the magnetic pole strength, is weber as well.

Here, on this paper, you can find magnetic field strengths, of some typical magnetic objects. Compare the data, to realise, how bigger or smaller, one tesla is.

Hope you realized the topic. Tell me in the Comment box, if you have cleared your doubt on this topic.

See you in our next tutorial. For now, let me say good bye.


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