Dropping a magnet down a copper tube: A demonstration of Lenz's law.

A simple demonstration of Lenz's law and the principles of Electromagnetic Inductions.
I realise that during my explanation I state that a current is induced in the copper tube. Strictly speaking this is not true: The motion of the magnet induces an EMF (a potential difference) and it is the EMF that drives the current. I wanted to keep my explanation quite simple, though, and so avoided talking about EMFs as I felt this could confuse some viewers.

[@Dady6798]

I really liked the format of this video with an explanation at the end. I have two questions though (english is not my first language, so I apologize in advance for eventual mistakes): 1) Since the the magnetic flux through the copper tube is a scalar product, we should only consider the magnetic field that is parallel to the axis of the tube. The current should follow a circular motion and, in each point, should be perpendicular to the radius. Using the right hand rule, wouldn't that mean that the magnetic force would push the magnet against the sides of the tube instead of slowing its motion, and wouldn't the total force be equal to 0, considering that for each point in the circumference there is an opposite one that creates an opposite force? 2) Would the result change if the magnet were dropped from the other pole?

[@QuantumBoffin]

Great questions! The current I was referring to tappers just in front of the magnet and loops around the tube. The causes that section of tube to act like an electromagnet, creating field lines travelled along the centre of the tube at that point (in accordance with the right hand grip rule). This field is in the opposite direction to the field of that magnet, and hence repels it. Put the magnet in the other way around makes no difference.

[@Dady6798]

@@QuantumBoffin Ok, I think I understood, thanks for the answer. So in an electromagnet the field lines would be directed towards the centre of the circumference and not the axis of the tube, correct?

[@QuantumBoffin]

In an electromagnet the field lines run through the centre of the magnet. One end of the coils acts like the North Pole of a magnet (and has field lines emerging from it) and the other end acts like a South Pole (has field lines entering at this point). The tube just in front of the magnet acts like a mini electromagnets. If the lower end of the magnet is a North Pole, then the upper part of the “electromagnet” will also act like a North Pole and so repel it.

[@Dady6798]

@@QuantumBoffin Alright, now it's perfectly clear, thank you :)

[@sarthakgarg6295]

New subscribers, excellent way of teaching !!

[@Aditya_Tiwari___]

Big fan sir😍😍😍

[@stumpy5353]

Is the rate of fall of the magnet inside the tube constant or does it differ on quantity of materials used or weight? If magnets of apposing poles where placed in the tube would this effect the speed at which it falls? thanks

[@QuantumBoffin]

The rate of fall depends on all kinds of things: The weight of the magnets The resistance of the copper tube The strength of the magnet. If you put two magnets down the tube, the outcome would depend on how close they are (ie does the magnetic field of one magnet affect the field of the other?)

[@tonihristovski3912]

I think that a fall velocity of the Radially oriented single pole ring magnet will be a greater (faster falling) than the Axially oriented cylindrical magnet (conventional magnet), of course, in a case of their equal: strength of magnetic fields, geometry and mass. Next time I could explain why my opinion is like this, but before that, I need to see this experiment and become 100% sure.

[@tonihristovski3912]

What will happen if we drop: radially oriented single pole, longer cylindrical-ring magnet in the cooper pipe? Whether the fall velocity, of the radially oriented single pole ring magnet, in the cooper pipe, will be faster, slower or same like the fall velocity of axially oriented cylindrical magnet, which is same longevity, diameter and intensity like previous one? Thank for your attention, and we hope that you will accept our suggestion to perform this experiment and show on KZbin.

[@QuantumBoffin]

Single Pole? You mean a magnetic monopole? If you buy me one then I'll do the experiment for you! 👍😎

[@aa-lr1jk]

Nice.

[@Devilzcallin]

Nice

[@phiddlephart7026]

How about dropping copper in a magnet pipe? I can't find anything on it. Get a iron pipe, cover it w magnets & drop copper thru it.

[@QuantumBoffin]

Great idea! Although to work, the copped needs to pass through the field lines, so you'd have to stick north poles to one side of the tubing, and south poles to the other. (It wouldn’t work if the tube was magnetised along it’s length). You can also create the same effect by attaching a piece of copped to a piece of string and swinging it, as a pendulum, between two opposing poles.

[@nothingnothing4857]

What if negatife pole beneath endless bop endless movement. We have +×÷=/%$ movement symbol is ?

[@nothingnothing4857]

Yeas you realy but is it possible ? A way more effecient way of creating Crypto currency.

[@nothingnothing4857]

Hmm i found a new theory could huge ball shaped cylinders catch air and cause a domple effect and squeeze the ammount inside a tube or pipe create big movement out of air ? Cliffs with the biggest wafe tossers have half cylinder balls when full it domples over. Or quarter like there where steamers with old way moles water way but wafes of cliffs way more power.