Recent content by girlinphysics

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    Are plane waves real/physical?

    When finding solutions to Maxwells equations we always cosider the case of a plane wave. But are plane waves real/physical solutions we can consider in real life? My guess is not because it is required to propagate infinitely. So why do we use plane waves to solve Maxwell's equations?
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    What is this version of the wave equation?

    Where does the refractive index come from?
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    What is this version of the wave equation?

    I came across this expression for the wave equation: \nabla^2E + \mu\sigma\frac{\partial{E}}{\partial{t}} - \frac{n^2}{c^2}\frac{\partial{E}}{\partial{t^2}} = 0 My question is what kind of medium is it for/where did it come from?
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    Teach Physics to GED Holder with No Math Background

    Khan Academy is a good place to start for really beginner level physics.
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    Laser that doesn't have a resonator?

    Is it possible to have a laser without a resonator? My guess is you can as you would still get some proportion of light coming from the inverted medium. My question is how would this light be different (from that of a laser with a resonator) and are there any practical uses for such a device?
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    Does the heat capacity change for a metallic system?

    This explains a lot, thank you very much for your answer!
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    Does the heat capacity change for a metallic system?

    In class we derived the relationship between temperature and heat capacity for the Debye model. We found that in 3D the heat capacity is proportional to temperature cubed. My question is, would this relationship change in a metallic system?
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    Did I get this right? Matrix system of a lens

    Oh okay, thank you very much for your help!
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    Did I get this right? Matrix system of a lens

    Homework Statement A thin lens is placed 2m after the beam waist. The lens has f = 200mm. Find the appropriate system matrix. This is a past exam question I want to check I got right. Homework Equations For some straight section [[1 , d],[0 , 1]] and for a thin lens [[1 , 0],[-1/f , 1]]...
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    Fermi level of n-type semiconductor Nd>Na>0

    Homework Statement This isn't actually a homework question, but in my semiconductors textbook, the following equation has been given: E_f = E_g - k_BTln(\frac{n_0}{N_d - N_a}) This is for the limiting case Nd>Na>0. I got a little confused as to where that equation has come from. Homework...
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    Reciprocal of the reciprocal lattice is the original lattice

    In my course we are currently studyinh Bravis lattices. We were told that the reciprocal of the reciprocal lattice is the original lattice. This is very easy to prove when given an example of a SC/BCC/FCC lattice, however, is there a formal proof for this?
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    How to find reciprocal lattice vectors

    Oh yes it was! I've edited it now, thanks.
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    How to find reciprocal lattice vectors

    So I know that the basis vectors of an FCC in a symmetric form are: a = \frac{a}{2}(\hat{x} + \hat{y}) b = \frac{a}{2}(\hat{y} + \hat{z}) c = \frac{a}{2}(\hat{x} + \hat{z}) And that the reciprocal lattice vectors are the basis vectors of the BCC cells. I'm having a hard time doing the...
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    Can I get a job in patent law with a physics degree?

    I am in my final year at university as undergraduate BSc student majoring in physics, and I am wanting to train in IP. I know about all the requirements and exams etc, my question is, am I at a loss compared to engineering students?
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