Asked in Inventions, Physics, Magnetism
Can magnets pull more than their own mass?
Of course., they can.. What matters is how much is magnetic power (being more specific, electrically magnetic flux.). The attraction between two magnets is tremendously high with higher flux density magnets. (if you are more interested to know about, can browse for neodymium magnets!). ...
Asked in Electrical Engineering
Why electromagnets over permanent magnets for a large dc machine?
The flux density of an electromagnet can be easily controlled. It's also easy and cheap to produce a large flux density with an electromagnet which is necessary for such large dc motors. Permanent magnets are generally expensive. For such a large motor,a very large permanent magnet will be needed for that motor which will not be ideal. Answer Electromagnets are more powerful than temporary magnets, and -as pointed out above- their flux density can be controlled. ...
Asked in Science
Why should the flux density increase with the speed of the magnets?
It is because induction of electricity depends on rate of change of flux and it means the speed of magnet ...
Asked in Cars & Vehicles
What are the Advantages and disadvantages of permanent magnets?
permanent magnets and wound stators (temporary magnets) can be used inthe generators and motors. in small size generators (eg: dynamo in cycle),permanent magnets are used because, 1 it does not require electricity to magnetise 2 does not require stator cooling but in larger size generators and motors, temporary magnets are prefered because, 1 it is small in size of same power permanent magnets 2 we can control the stator magnetic field by adjusting the power 3 the magnetic flux density per square cm is more etc.. ...