Hey guys, i finally started UNIT 4 AOS 1 and I am a bit confused on somethings.
Firstly, i think my main problem is not understanding how a magnet works. Like what is flowing around a magnetic field? Electrons? What makes them move around exactly? What actually gives a magnet it's magnetism? More in the sense of a permanent magnet? How does this relate to the poles of a magnet. Is it what is inside a magnet that makes it magnetic, or does it relate more to it's magnetic field? What is different between the two poles and how can atoms/electrons(??) in a magnet form different poles. Does it stop and end at a certain point in the middle? I guess one of my questions is, what exactly is the field made out of and/or does anything flow in the field? How is this different/the same as a gravitational field?
I think this might tie into what we learn later, but my textbook says that a piece of iron will have magnetism induced in it when placed in an external magnetic field. Is this specific to Iron? Will it create it's own magnetic field or just use the other one, and how exactly does any of that work? My book explains that it happens but says it is somehow induced the piece of iron to become a magnet?
What is the difference between the grip and palm rule? I feel like they are doing the same thing. Well i understand the grip rule; your thumb shows the direction of current in a wire and your fingers will show the direction of the magnetic field. While the palm rule does the same then but then also shows the force? My book says that it gives the direction of the force on a current carrying wire placed in an external field? Does this mean it always involve >2 magnets pulling each other?
This one might be a bit hard for me to explain, but in a simple rectangular magnet, we always see that the fields always come from the two poles. And i know these are just illustrations, but how many field 'lines can actually come out of a magnet? Are there actually space in between all of them or do they fill up all the space it can? How much distance is between each field 'line'? Do all the field 'lines' come back to the south pole of the same magnet? Sometimes it looks as if there is a straight line coming out of the top of the magnet, where does this go. Does it just stop? Also, probably just bounded by book illustrations, but do all the field lines go out in all directions. Does it form an 'oval' shape around the entire magnet? And then would a magnetic field around a length of wire form a cylindrical shape around the wire?
This might not make sense because i might be totally confused and wrong.In my book there is an equation for the strength of an electric field written as
. What exactly is the constant K? Is it referring to, like if the magnet was is space or in air or underwater?
Lastly, i got up to the force on a wire carrying a charge in a magnetic field. Probably still relating to the palm rule question, where and what is this force exactly? Secondly I'm a bit confused with the equation. We have
which I understand, but then we 'derive' it to
. I understand that the B force needs to be perpendicular to the current from the pictures in my textbook, but i don't understand how we find B perpendicular. I also got confused with this in Torque when i did the detailed study.
Is this picture a correct way of doing it? Can we just use cos as well? Sometimes i feel i can just use cos of an angle and it makes it easier.
Really lastly, my book has a part talking about how we express the relationship between the 3 vectors Force, Length and Field though vector cross multiplication. It says that 'if we write F = Il x B this is taken to mean that the magnitude of vector F is the product IlBsin(theta)'. I know this might be a bit more maths now, but how does the cross product work to get this, and is this the same way they find Torque as well?
I don't expect anyone to answer every question, but thanks to anyone that can help at all. I did try to find some of my answers elsewhere before looking here, but i didn't really find anything that helped.