Where science meets magic and fun meets education!

Lenz's Law Demo

(Code: 24)
Add to cart
Lenz's Law DemoIf you drop the little metal slug down the copper tube, it falls under the pull of gravity, and drops out at the bottom, just as you would expect.But take the second, apparently identical, slug; drop it down the tube, and hey presto! the slug travels down the tube extremely slowly. You can even see it's slow passage via the window in the side of the tube.It is a great magic trick, but the truth is just as amazing. The second slug is highly magnetic. Now Michael Faraday, the British physicist, discovered as long ago as 1831 that when you pushed a bar magnet into the opening within a copper coil, an electric current was produced within the coil. This is known as electromagnetic induction.The Russian physicist Heinrich Lenz observed that the direction of the induced current in a conductor is always such as to oppose the motion which produced it.So as the magnetic slug moves down the copper tube, a series of transient "eddy currents" are induced in the copper tube, and these currents will create a magnetic field that opposes the downward motion of the slug.CONTAINS MAGNETS. SUITABLE FOR CHILDREN 14 YEARS AND OVER

  1. #Video#
Customer reviews
Steve Panichelli Review collected by Feefo
cameron mclean Review collected by Feefo
Great product. Well packaged and pleased to find this unusual item online.
Alison Jones Review collected by Feefo
Just what I needed.
Palle Kroeis Review collected by Feefo
George Butcher Review collected by Feefo
Lenz's Law: This could be improved with a smaller viewing port, so that the retardation effect is more pronounced.

Other purchases:

Heatmobile2: Very good, but subject to rust on the lower axle. Thus, it requires periodic servicing for optimal function.

Tippe Top (small): Durable and very well produced.

Inverter Magnet kit: impressive. Perhaps it could be sold with the small scale to determine friction of table and hence enable field-strengths to be estimated.
John Douglas Hey Review collected by Feefo
Lutz Ohlwein Review collected by Feefo
It works, although the buffer pads on the magnets / weights could be better secured, and had to be re-glued after a few demonstrations.
Steve Ellis Review collected by Feefo
The plastic elements quickly fell from the magnet, I had to glue them back. Still, the thing does what it's meant to. I'm very satisfied.
Mathieu NOGARET Review collected by Feefo
Ash Mathur Review collected by Feefo