How to Prove E and H Satisfy Maxwell's Equations?

  • Thread starter Thread starter likephysics
  • Start date Start date
  • Tags Tags
    Maxwells equations
likephysics
Messages
638
Reaction score
4

Homework Statement


I am trying to solve prob 4.107 in Schaums' Vector analysis book.

Show that solution to Maxwells equations -

\DeltaxH=1/c dE/dt, \DeltaxE= -1/c dH/dt, \Delta.H=0, \Delta.E= 4pi\rho
where \rho is a function of x,y,z and c is the velocity of light, assumed constant, are given by

E = -\Delta\phi-1/c dE/dt, H= \DeltaxA

where A and \phi, called the vector and scalar potentials, respectively satisfy the equations
\Delta.A + 1/c d\phi/dt =0
\Delta^2 \phi - 1/c (d^2 \phi/dt^2) = -4pi\rho
\Delta^2 A = 1/c^2 (d^2A/dt^2)

Homework Equations





The Attempt at a Solution



I don't understand the problem. Should I show that E = -\Delta\phi-1/c dE/dt, H= \DeltaxA satisfies the vector and scalar potential equations?
 
Physics news on Phys.org
Hi likephysics! :smile:

(have a delta: ∆ and a phi: φ and try using the X2 tag just above the Reply box :wink:)
likephysics said:
Should I show that E = -\Delta\phi-1/c dE/dt, H= \DeltaxA satisfies the vector and scalar potential equations?

No, you should assume that the A,φ equations are satisfied, and then prove that E and H (derived from A and φ) satisfy Maxwell's equations. :smile:
 
tiny-tim said:
No, you should assume that the A,φ equations are satisfied, and then prove that E and H (derived from A and φ) satisfy Maxwell's equations. :smile:

I disagree, that seems to be proving the reverse statement of what the problem statement asks for.

I would assume that E and H satisfy Maxwell's equations (so that they are solutions to said equations, as per the first premise of the problem statement), then substitute in your expressions for them in terms of the vector and scalar potentials (the second premise of the problem statement) and use appropriate vector product rules to show that Maxwell's equations, in terms of the potentials, reduce to the final 3 equations you are given (the intended conclusion).
 
Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
The value of H equals ## 10^{3}## in natural units, According to : https://en.wikipedia.org/wiki/Natural_units, ## t \sim 10^{-21} sec = 10^{21} Hz ##, and since ## \text{GeV} \sim 10^{24} \text{Hz } ##, ## GeV \sim 10^{24} \times 10^{-21} = 10^3 ## in natural units. So is this conversion correct? Also in the above formula, can I convert H to that natural units , since it’s a constant, while keeping k in Hz ?
Back
Top