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

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SUMMARY

This discussion focuses on proving that the electric field E and magnetic field H satisfy Maxwell's equations using vector and scalar potentials. The equations under consideration are ΔxH = (1/c) dE/dt, ΔxE = -(1/c) dH/dt, ∆·H = 0, and ∆·E = 4πρ, where ρ is a function of spatial coordinates and c is the speed of light. Participants clarify that one should assume the vector potential A and scalar potential φ satisfy their respective equations and then demonstrate that E and H, derived from A and φ, fulfill Maxwell's equations.

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  • Understanding of Maxwell's equations and their implications.
  • Familiarity with vector calculus, particularly the Laplacian operator (Δ).
  • Knowledge of vector and scalar potentials in electromagnetism.
  • Basic principles of electromagnetic theory, including the relationship between electric and magnetic fields.
NEXT STEPS
  • Study the derivation of vector and scalar potentials in electromagnetism.
  • Learn about the application of the Laplacian operator in physics problems.
  • Explore the implications of Maxwell's equations in different physical contexts.
  • Investigate the relationship between electromagnetic waves and the speed of light (c).
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Students of physics, particularly those studying electromagnetism, as well as educators and researchers looking to deepen their understanding of Maxwell's equations and their applications in theoretical and applied physics.

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Homework Statement


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

Show that solution to Maxwells equations -

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

E = -[tex]\Delta[/tex][tex]\phi[/tex]-1/c dE/dt, H= [tex]\Delta[/tex]xA

where A and [tex]\phi[/tex], called the vector and scalar potentials, respectively satisfy the equations
[tex]\Delta[/tex].A + 1/c d[tex]\phi[/tex]/dt =0
[tex]\Delta[/tex]^2 [tex]\phi[/tex] - 1/c (d^2 [tex]\phi[/tex]/dt^2) = -4pi[tex]\rho[/tex]
[tex]\Delta[/tex]^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 = -[tex]\Delta[/tex][tex]\phi[/tex]-1/c dE/dt, H= [tex]\Delta[/tex]xA satisfies the vector and scalar potential equations?
 
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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 = -[tex]\Delta[/tex][tex]\phi[/tex]-1/c dE/dt, H= [tex]\Delta[/tex]xA 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).
 

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