Electromagnetism Definition and 829 Threads

  1. H

    Why Does a Charged Disk Generate a Non-Zero Electric Field at Its Center?

    I have two questions. The first concerns a charged disk. Consider the center of the surface of the charged disk, O. Mathematically, the value of E at O comes out to be a non-zero finite value. However i am having difficulty linking this with the physical sense. The disk can be thought to be...
  2. Q

    Electromagnetism to deviate the path of an incoming bullet

    Hello,everyone I was thinking if electromagnetism could be used to deviate the path of an incoming bullet?
  3. N

    What are some useful websites for basic electromagnetism?

    hey all ... can i have sites 4 basic electromagnetism ? i would be so grateful to u ... cheers abc
  4. L

    Electromagnetism everyone's favorite

    Hi again guys. I've got a test charge place a certain distance away from a large flat uniformly charged non-conducting surface. I'm told what the force charge is from this distance. Then the test charge is moved, and I'm supposed to say what the force on the test charge is now. I tried doing it...
  5. G

    Electromagnetism homework question

    1. A simple generator has a 200-loop square coil 25.0cm on a side. How fast must it turn in a 0.550T field to produce a 120V peak output? area=(0.25)^2 =6.25x10^-2 E=-N(BA)/t t=-(300)(6.25x10^-2)(0-0.550T)/120V t=8.6x10^-2 s do you need to times it by 4 to get the time for one...
  6. S

    Electromagnetism in my physics class

    Well I was learning bits about Electromagnetism in my physics class and we were learning about transformers and thought it was kind of neat. I was just wondering why transformers use alterneting current and why power must be delivered at such high voltages across transmission lines? Also, how...
  7. B

    Questions concering magnets and electromagnetism

    I am a bit confused about the concept of magnets. It is said that magnets attract opposites, and repel likes. Now does that refer to the material, or a magnet being attracted/repelled by another magnet? Also... If an electromagnetic apparatus is strong enough, will attract/pull just about...
  8. R

    How Does a Conducting Loop's Size Affect EMF and Motion on an Inclined Plane?

    A small conducting loop of mass m,radius r,resistance R is released from rest along a smooth inclined plane such that the plane of the loop is perpendicular to a magnetic field which varies along x-axis as B=B'(1+ax).here B' and a are constants.Find the speed of the ring as a function of time...
  9. R

    Why does x1i =r1 -y1j in Lorentz electromagnetic force?

    When going over my notes on the lorentz electromagnetic force in my physics 3 electromagnetism class got a bit puzzled by one statement that seems just to be taken for granted. Could anyone help me and tell me why x1i =r1 -y1j on page 5 on...
  10. K

    Is electromagnetism's symmetry affected by the composition of particles?

    Quarks can't exist in isolation and the electric charge on quarks can't exist in isolation from the electric charges of other quarks either.The electric charge of leptons like the electron can exist in isolation.Isn't electromagnetism showing a kind of asymmetry here: symmetry could be restored...
  11. L

    How Does Increasing Coil Turns Affect Electromagnetic Force in a Solenoid?

    An electric current passing through a coil of wire generated an electromagnetic effect.What effect does the number of turns of wire in a coil have on the size of the electromagnetic force? What hypothesis can u form and how do you use the domain theory to support this??
  12. D

    Simple electromagnetism question

    hi, i have a question, if you could help me, that'd be great: why does a smaller diameter coil result in a stronger electromagnet??
  13. K

    Higgs particle and electromagnetism

    The Higgs particle may never be found - Stephen Hawking doubts that it exists. If mass isn't due to the Higgs, could it be caused by electromagnetism? For example, if protons and electrons experience resistance to a change in their speeds from charged particles in the space around them,could a...
  14. S

    Question: Electromagnetism, Weak-force, Gravity, Strong Nuclear force ?

    Great work has been done in the last while on the Four fundamental forces, but is there a fifth ? Is there a Force Number 5 :confused: ? I saw a discussion on this other website http://www.thespacesite.com/community/index.php?showtopic=199 :surprise: QUOTE: the age of the...
  15. K

    Where Can I Find Comprehensive Electromagnetism Notes Online?

    anyone who has some notes? or website where you can find em? i have tried google but with no luck need it! thanks guys!
  16. T

    What are the four equations that describe electromagnetism?

    What are the four equations that describe electromagnetism? (please leave an explanation to the letters)
  17. B

    Is Your DIY EMP Device Safe to Use?

    I have constructed an EMP emitter device via some plans.. then i jacked it up to give it some more power. but, alas, i have scared myself. It is just a straight up electromagnet pulse generator, no microwaves or anything else (i am assuming, unless it generates them and i don't know yet...
  18. P

    Need help with electromagnetism problems?

    OK first off I'd like to thank Warr for helping me with one problem again thanks a lot Okay now to business I have an ISU (Independent Study Unit) due this thursday and I'm pretty much all done, but it would be great if you guys could just look over it for any mistakes and or advices. ISU...
  19. M

    Electromagnetism and the photon

    Theories in physics are often said to follow one another . This statement is both true and false . The development of a new theory does not necessarily invalidate the old theory , but often results in making the latter a particular or limiting case of the former . For instance Newtonian...
  20. J

    Electromagnetism and the photon

    A simple question: The force carrying particle for electromagnetism is the photon. Is the photon traveling from the N-pole of a magnet different from the photon traveling from the S-pole of a magnet? If not, how do the fields/photons know whether to attract or repel?
  21. I

    Comparing Gravity and Electromagnetism

    Am interested in comparing gravity with electromagnetism. What are the differences in properties between the forces and how are they alike?
  22. K

    Can Moving Charges Create a Magnetic Field? A Discussion on Electromagnetism

    Hi, I would like to clarify some points on electromagnetism. Most (if not all) of my teachers say that moving charges create a magnetic field. I would just like to know... relative to what? If two electrons move parallel to each other with the same velocity, would they show any magnetic...
  23. T

    Electromagnetism Question: Electrons in Motion and Magnetic Fields Explained

    for example, there is an electron moving at some speed in a straight line. a circular magnetic field is produce(just like electron moving in a line of wire). if there's a n observer moving along with the electron, then the electron will appear to be at rest with the observer. does it mean that...
  24. S

    Myron Evans O(3) Electromagnetism

    Afther a bit of research i have at last found the right place to learn about the Miron Evans theory. It is here: http://www.aias.us/ From the many papers enumerated there i have foudn that these could be one of the most self-contained: http://www.aias.us/Note05182003/finalwaveeqnms.pdf...
  25. M

    How to Calculate Total Force on a Charge at the Center of Curvature?

    help! I need help with this homework problem. --A line of positive charge is formed into a semicircle of radius R=60.0 cm. The charge per unit length along the semicircle is described by the expression [lamb]= [lamb]naught cos [the] . The total charge on the semicircle is 12.0...
  26. C

    I have studied electromagnetism in my Physics AP class

    Hi, I'm new here so I'm not sure how formal this should be: I have studied electromagnetism in my Physics AP class at my high school but I have had a question at the back of my head. I don't have a very good physics teacher, and he was unable to explain this to me. My question is why, when...
  27. M

    How Is Force Calculated on a Charge at the Center of a Charged Semicircle?

    help! I need help with this homework problem. --A line of positive charge is formed into a semicircle of radius R=60.0 cm. The charge per unit length along the semicircle is described by the expression [lamb]= [lamb]naught cos [the] . The total charge on the semicircle is 12.0...
  28. M

    Some questions on electromagnetism

    dear friends there are some theoretical questions in my mind about electromagnetism 1) in RL circuits the induced emf starts to decrease from its maximum value to zero and this is caused by the changes of flux but why does the magnetic flux changes initially very rapidly and then starts to...
  29. A

    Electric Displacement Vector D and Magnetic Intensity Vector H in Electromagnetism?

    I can understand what the electric field vector E and the magnetic flux density vector B mean, but what exactly are the meanings of the two other vectors, the electric displacement vector D and the magnetic intensity vector H? What are their physical explanations?
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