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    2-D Waves: Relation of power with radius

    As I understand, power is directly propotional to amplitude squared for all waves. In the 2-D case, how will power depend on 'r'? For plane waves, the wavefunction is exp(ik.r) and multiplying it with its complex conjugate gives a constant amplitude and thus a constant power (I think). But...
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    Schools Applying to Grad School without Research Experience

    Hi, I'm going to apply for grad school this fall. I'm an international student from Pakistan. Although I don't have extraordinary credentials, but I think I satisfy the minimum - top 10% of my class. I'm also confident of scoring high on GRE Physics as some trials have went unexpectedly well...
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    Trigonal lattice with each angle equal to 120degree

    1. What happens when the angles between the three sides of a trigonal reach 120degrees? I know that at 90degrees, it becomes a simple cubic. At 109degrees, it becomes a body centered cubic. At 60 degrees, it becomes a face centered cubic. What about 120degrees? I think that perhaps it should...
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    Acceleration Tensor - Rotating Frame

    If a coordinate system is rotating, that is time 't' is not independent, then does the acceleration transform as rank 1 tensor? I thought that it wouldn't because when time is changing, so acceleration will change in a more complicated way than a rank 1 tensor. Perhaps as a rank 2 tensor...
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    Vector Potential: How to Find it?

    Vector V=x^2i+3xz^2j-2xzk The divergence of this vector is zero. So it can be expressed as the curl of a vector. I have to find that vector, which is also called the vector potential. But I don't know how to find it. When I have to find the scalar potential, then it is easier to equate...
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    Transformation Matrix Problem

    I don't know if this is the right section, but this problem is in my electromagnetism course (Griffiths text). This is problem 1.9 of Griffiths (3rd edition) text: Find the transformation matrix R that describes a rotation by 120 degrees about an axis from the origin through the point...
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    Crystal Planes, Miller Indices: Cubic Lattice

    Just when I thought I understood the concept of planes and miller indices, I got stuck on a 'test your understanding' Q in my book. I can't understand that there can be two or more (110) planes in a crystal lattice? I thought there can be only one such plane. The question asks me to find the...
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