# Tagged Questions

58 views

### Magnetic field resistance material: are there any? [duplicate]

I was wondering with a question for a quite long time, thought to ask here. I need to know is there any material or element which can block magnetic field? I mean I am searching for such material or ...
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### What are the implications of running a motor well above its rated frequency?

Plenty of material on the web will tell you what to expect when you run a 50/60Hz 3-phase induction motor at 60-80Hz, but what if you would like to run it at 140Hz? or 250Hz? Or at any frequency? ...
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### Force of electromagnet on piece of iron

I can find equations to give the force of an electromagnet on a piece of iron when the iron touches the electromagnet. But what about when the iron is some distance from the electromagnet? ...
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### Can an induction coil heat two layers of metal?

Imagine we have an induction coil which is strong enough to heat a sheet of metal. We can put a sheet of ferromagnetic metal close to the coil at distance $h_1$, and it gets heated to temperature ...
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### What could be some applications for a highly compressed magnetic field?

If you had a powerful electromagnet in the shape of a hollow sphere in which the top and bottom halves are the opposing poles, what can the magnetic filed at the center of the sphere be used for?
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### Magnetic flying engine [closed]

I invented a flying engine moving entirely by magnetic forces (such as the force related with magnetic field of the Earth). See http://porton.wordpress.com/2011/12/23/magnetic-vehicle/ The question ...