Recent content by drumercalzone

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    Transformer, AC Source, and a Battery

    Thank you for your help! It just seemed too easy!
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    Transformer, AC Source, and a Battery

    Homework Statement Using an AC signal generator vs, a transformer with turns ratio n = 1, and a battery VB, sketch a circuit that will generate the output signal vout = vs + VB Homework Equations \frac{V_2}{V_1} = \frac{N_2}{N_1} The Attempt at a Solution Here's my sketch...
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    What is the impedance of a tank circuit at resonance?

    Homework Statement a) Determine the impedance of this circuit. b) What is the impedance when \omega = \frac{1}{\sqrt{LC}} Homework Equations The Attempt at a Solution EDIT: I got the Z wrong. It's Z = \frac{L}{C(j{\omega}L - \frac{j}{{\omega}C})} For part b, I'm...
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    Magnetic Moment of a Charged, Rotating Sphere

    Bah. I don't know why this is eluding me. Here's where I am now: dq= \frac{q}{4{\pi}r^2}da , da=2{\pi}rdr therefore: dq = \frac{q}{2r}dr (Here r is the radius of the slice, I'll use R for radius of the sphere). However I don't think that I have my da right. What's the...
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    Magnetic Moment of a Charged, Rotating Sphere

    Originally I thought that surface area would come into play, but I think that since we're worried about Current Areas maybe not? I feel like there should be a dq in there somewhere. So maybe two integrals?
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    Magnetic Moment of a Charged, Rotating Sphere

    Okay, so for the area, I could integrate from 0->R twice to sum all the cross-sectional areas of the sphere: A = \pi r^2 therefore dA = 2{\pi}rdr and A_{total}=2\int_0^R \! 2{\pi}rdr and A= 2{\pi}R^2 Now we have: \vec{\mu} = \frac{q}{T} \frac{2{\pi}R^2}{c} =...
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    Magnetic Moment of a Charged, Rotating Sphere

    Homework Statement Show for a solid spherical ball of mass m rotating about an axis through its center with a charge q uniformly distributed on the surface of the ball that the magnetic moment \mu is related to the angular momentum \vec{\mu}={\frac{5q}{6mc}}\vec{L} Homework...
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    Spherical Harmonic Wave Function =? 3D Wave Function

    Homework Statement Prove that the spherical harmonic wave function \frac{1}{r}e^{i(kr-{\omega}t)} is a solution of the three-dimensional wave equation, where r = (x^2+y^2+z^2)^{\frac{1}{2}} . The proof is easier if spherical coordinates are used. Homework Equations Wave function...
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    Find the Current Through a Resistor with a Constant Current Source

    Thank you so much for your help! I'm definitely going to look into the Conductance thing there. It looks like a very valuable tool.
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    Find the Current Through a Resistor with a Constant Current Source

    Well let's see: \frac{1}{R_{eq}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} Which I got to: \frac{1}{R_{eq}} = \frac{R_1R_2 + R_1R_3 + R_2R_3}{R_1R_2R_3} Which means: R_{eq} = \frac{R_1R_2R_3}{R_1R_2 + R_1R_3 + R_2R_3} Then I'd plug that in V = IR_{eq} and get: V =...
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    Find the Current Through a Resistor with a Constant Current Source

    Thanks for the quick reply! I see where you're getting at - makes the math much simpler, but we haven't covered conductance yet. Is there any other way around the problem, or do I just have to do some nasty algebra?
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    Find the Current Through a Resistor with a Constant Current Source

    Homework Statement Hey everyone. I might be overthinking this one, but I thought I'd post it. (sorry for the crappy MS Paint sketch!) I need to find the current through R3 Homework Equations V=IR \SigmaV=0 (around a closed loop) \SigmaI=0 (going into a junction) The Attempt...
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