1. A

    Calculating the divergence of electric field using the definition of divergence.

    If I try to calculate the divergence of electric field created by a point charge at the origin then I shall do something like this: \mathbf{E}= \frac{1} {4\pi\epsilon_0} \frac{q}{r^2} \hat r \mathbf{\nabla} \cdot \mathbf{E} = \frac{1}{r^2} ~ \frac{\partial (r^2E_r)}{\partial r} +...
  2. muon

    varying vev for a scalar field of complex charge, such as as the Higgs field

    Here is some background for my question, which is as I currently understand it (meaning, it may be wrong): In a self-interacting scalar field, the formula for potential energy can be given as (μ^2 * (Φ^2)/2) + (λ * (Φ^4)/4). In a field with an imaginary value for μ, μ^2 becomes negative...
  3. A

    Electric Field for the circular path of positively charged particle

    Here is picture. Answers is A. My attempt was that I thought if i were to place a positive test charge then it would go from top to bottom if there was a positive charge in the center it was avoiding and a positively charged particle at the top, but an...
  4. F

    Finding the electric field along the line between charges

    Hey So I've been asked this question as part of my physics assignment (Its an advanced section question so significantly harder than the normal questions) and I've been stuck, my intuition tells me there should be two zero points, and initially I found a formula that only found one, however...
  5. B

    Direction of Electric Field lines

    Hello, I understand how to get the magnitude for the electric field in this problem. My only issue is that I cannot figure out why the i coordinate is -sin while the j coordinate is -cos. I had the problem entirely right except I had cos in the i spot and sin in the j spot. I'm sure this is a...
  6. K

    Magnetic field of a spinning electron?

    What sort of magnetic field does a stationary spinning electron have? Is it the same as the magnetic field of a rotating sphere or spherical shell?
  7. F

    Electric field, in the vertices of a triangle

    in triangle ABC there are charges qa =-1.7X10-7C and qb =5.3X10-7. Find the intensity of the electric field in the vertex C
  8. A

    Electric field in conductive solutions

    Goodmorning everyone, i'm knew to the forum (so please excuse me if i make obvious mistake) and i mainly joined in the hope to find some help with a question that i have on electric field. Due to some experiment i'm doing i found my self looking for some theoretical prediction of the...
  9. N

    Earth's magnetic field strength using Galvanometer

    I have deleted my post due to lack of reply/interest.
  10. S

    Modifying Einstein's field equations

    Hello everybody, Since quite a while I am working on an emergent gravity theory. I have explored it in many ways, but what I haven't done is write down particular field equations for it. There is something analogous to space time curvature in my model, and basically the left side of...
  11. Blaze

    concentrated magnetic field

    Hi I want to make a strong magnetic field using electricity. and concentrate it in a small point. I can't use a core other than air. (actually the core will be plasma) I have to implement a tube with a very big length-diameter ratio. so the best applicable procedure I think is : make...
  12. F

    Electric field strength between two rings:

    Hi to everyone! I'm here to ask how could you resolve this problem about electric fields: two charges q1= 1.88*10^-8 and q2=-7.54*10^-8 are evenly distributed on two rings with the same radius R=30 cm, positioned above two parallel planes, far each other d=3mm. We have to calculate the strength...
  13. H

    What do the "directions" of a magnetic field mean

    Hi ok so I have an emf scanner on my phone and it shows 3 axes, x y and z. A: What do those mean about the magnetic field? And also, B: why does the scanner drop down to near 5 or 1 µT (average is 40-50 µT) at random spots in the wall or ground?
  14. D

    Electrons in Quantum Field Theory

    Electrons in quantum field theory are an expanded field. They have infinite lengths. How does electron transfer in an triboelectricity or chemical process, how does the principle of the exclusion of Paul's work, which says that fermions can not occupy the same place?
  15. F

    help with magnetic momentum and particule in a field

    Sigh..... so 2 books, later, a few points under passing grade, and after getting no response from the online teacher , i spent the last 2 days diving in electricity maths books, and still manage to get wrong answers....what gives!!! plz help!! i need to get these right...
  16. C

    What is the magnitude of the magnetic field?

    ok this is my overleaf file but not sure how to solve this mahalo much(Cool)
  17. C

    what magnitude of uniform magnetic field are needed

    $\textsf{ You wish to hit a target from several meters away with a charged coin having a mass of $4.2 g$ and charge of $+2400 \, \mu C$}\\$ $\textsf{The coin is given an initial velocity of $14.0 \, m/s$, and a downward uniform electric field strenght $29 \, N/C$ exists throuhout the...
  18. K

    Direction of Magnetic Field

    Hello, I'm a bit confused on determining the direction of the magnetic field in the attached image. From what I understand, for the top wire, the magnetic field points into the page. For the bottom wire, the magnetic field points out of the page. But what is the direction of the magnetic...
  19. A

    Magnetic field inside

    What happens to the magnetic field inside this solenoid, if you double the number of revolutions, simultaneously stretching the solenoid twice as much as the original length? Suppose that the applied voltage was kept constant, and the additional wire length for additional turns of the coil did...