what are eddy current why it is desirable as well as undesairable
Answers
Answer:
we know that metals like silver and copper are excellent conductors possessing high number of free electrons (unbound to specific nucleus). Try dropping a bar magnet inside a hollow cylindrical rod made of such metals. The rod is repelled on its way as if the whole rod is magnetised in opposite sense. Repeat the experiment by interchanging north-south poles before dropping. The magnet is again repelled.We can understand that copper is certainly not magnetised just like the one in bar magnet! Looking over Faraday's experimental laws of electromagnetic induction, we can understand that there must be current produced (free electrons) in a circular sense horizontally on the rod because of the change in magnetic flux produced by magnet, to oppose such a change (Lenz law, sorry for long sentence). When current produced opposes flux, it consequently opposes the motion of magnet. This current is called eddy current.
Eddy current is necessarily not undesirable considering their power wasting effects in transformers. As it can damp motion of metals relative to magnetic field, it can be used in braking systems of metallic vehicles like some trains.
Explanation:
Answer:
We can induce currents not only in conducting coils but also, in conducting sheets or blocks. In the case of ... However sometimes eddy currents are desirable.