Recent content by physicsboy

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    Solving Skin Depth for Copper at 1.0 GHz

    You've got to understand what skin depth is and you'll get this question. When you solve Maxwell's equations in a conducting material, you get a complex wavenumber (i.e. a complex dielectric constant) and that imaginary part of the wavenumber leads to a decay of the wave in the conductor...
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    Question about number operator and density operator

    In quantum stat. mech. the average of any quantity is defined as \overline{A} = Tr(\rhoA) Where "rho" is the density operator.
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    QM: Harmonic oscillator expectation value of position for t>0

    Are you currently studying perturbation theory? This might be the way to approach the problem if so. However I have a sneaking suspicion that it is simpler than we are making out to be. What I tried is as follows: \langle \psi(t)|x|\psi(t) \rangle = \langle 0|e^{\frac{iHt}{\hbar}} x...
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    Magnetostatics: Find B in Cylindrical Pipe w/V, \zeta, a, L

    The voltage on the plates creates a uniform electric field inside. E=vL. You can use the idea that the current density is proportional to the electric field. J=\sigma E where \sigma is the conductivity. Use the Maxwell equation curl(B) = (4\pi)/c J and integrate it over a cross-sectional area...
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    Normalize both ψ1 and ψ2 and then find the energy eigenvalues of each

    Mr. Joshr, You've got the normalization correct. If you find the eigenvalues of the Hamiltonian you'll discover that they are plus/minus root 5. You would expect these to be real since your matrix is Hermitian (which it should be since this is supposed to represent an observable - namely the...
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    The concept of Rotation in 3-d in QM

    The mathematical content is contained in the ket itself. The phase factor multiplied infront does not change the "direction" of the ket but only scales it (makes it shotrter or bigger).
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