Which material is best for making a permanent magnet?
...Which material is best for making a permanent magnet?
Aluminum
cobalt
copper
soft iron
steel
Correct answer is E
Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferrite
Permanent magnets are made from special alloys (ferromagnetic materials) such as iron, nickel and cobalt, several alloys of rare-earth metals and minerals such as lodestone.
When a nonmagnetic piece of steel is applied to a magnet, the atoms within it rearrange themselves in a manner that creates a permanent magnet.
The instantaneous value of the induced e.m.f as a function of time is ε = εo sin ωt where εo is ...
From Newton's first law of motion, ...
In an A.C circuit, the ratio of r.m.s value to peak value of current is ...
The length of an iron bar is 100cm at 20°C. At what temperature will its length increase by 0.01...