What is the difference between electromagnet and solenoid? Both these terms seem as the same thing to me. The only difference that I can find seems to be that an electromagnet contains a soft iron core. I'm sure there must be some other difference between the two and I hope someone can clear this matter up for me.
[Physics] the difference between electromagnet and solenoid
electromagnetisminductanceterminology
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Theoretical physics is the field that develops theories about how nature operates. It is fundamentally physics, in that the ultimate goal is to describe reality. It is informed by experiment, and at the same time it extends the results of experiments, making predictions about what has not been physically tested. This is accomplished using the language of mathematics, and often the demands of theoretical physicists force mathematicians to extend this language in new directions, but it is not concerned with developing the language of math. Theoretical physicists are, among other things, physicists who are very well-versed in math (which is not to say other physicists are not - please don't hurt me).
Mathematical physics, on the other hand, is a branch of mathematics. It explores relations between abstract concepts, proves certain results contingent upon certain hypotheses, and establishes an interlinked set of tools that can be used to study anything that happens to match the relations and hypotheses on hand. This branch in particular is motivated by the theories used in physics. It may seek to prove certain truths that were simply assumed by physicists, or carefully delineate the conditions under which certain theories hold, or even provide generally applicable tools to physicists, who can in turn apply them to nature. Mathematical physicists are mathematicians who are intrigued/inspired by physics.
One could say that mathematical physics is concerned with the internal, logical consistency of physical theories, while theoretical physics is concerned with finding the right model to describe the world around us. Very roughly, one might diagram these things as shown below. $$ \text{Mathematical physics} \Longleftrightarrow \text{Theoretical physics} \Longleftrightarrow \text{Experimental physics} $$
A solenoid induces a magnetic field in the iron bar kept inside it. This is not the same as inserting a permanent bar magnet inside the solenoid.
The induced magnetic field is in the same direction as the original magnetic field. One way of thinking about this is that the domains in the iron bar line up with the external field, producing a net magnetic field in the same direction as the original.
However if you consider a permanent bar magnet kept in a solenoid, and the solenoid was large enough such that the bar magnet could rotate in any arbitrary direction, once the solenoid is switched on, the bar magnet will align itself with the solenoid's field. This has to do with minimizing the energy in the magnetic field. The energy is given by $$ E = - m .\vec{B} $$
so clearly if $m$ and $B$ are in the same direction, it is a lower energy configuration than if $m$ and $B$ are in opposite directions.
Best Answer
An electromagnet is a made coil associated with a ferromagnetic core. This way, the strength of the magnet is controlled by the input current.
A solenoid is a simple shape used in magnetostatics or magnetics. Like the plane or the sphere in electrostatics, the 1-turn coil in magnetostatics, its study is interesting because the calculus of the magnetic field inside is doable. Moreover, the solenoid produces a pretty uniform field inside, if you are neglecting edge effects.
So you could say that the solenoid is interesting because of the uniform magnetic flux density inside, and the electromagnet because of the non uniform magnetic flux density outside (an electromagnet may be done with a solenoid).