Recent content by ResonantW

http://www.ted.com/talks/eric_giler_demos_wireless_electricity.html In this video, I have two questions: 1) Why have a capacitor as part of the two circuits? Is it so no actual current flows around the coils, that's all I could come up with. 2) In the picture he shows of the two...

Griffiths brings up a point that it might make sense that current in a fat wire would want to concentrate itself mainly along the axis of the wire, given that parallel wires attract each other. He then asks us to figure out why this might not happen, but to be honest I would think it should...

I get that P= 6e22 esu/cm^2. Is that equivalent to the surface charge density? I can also express this as 1.3e32 electrons per square centimeter.

Got it! Why wouldn't the first method work? Also, do I know the volume density of water molecules, because that would be what Purcell calls N, correct?

Homework Statement Imagine that all the molecular dipoles in a cup of water could be made to point down. Calculate the magnitude of the resulting surface charge density at the upper surface of the water, and express it in electrons per square centimeter. Homework Equations The...

I'm currently a second-year university student considering applying to a PhD program in physics. I'm leaning towards theoretical physics, although I haven't really experienced enough to make a clear decision. I'm beginning to be involved in research with a theorist this semester, but I was...

In an AC circuit, the average power dissipated is given by P=VIcos(\phi). Does that mean that in a highly inductive, or highly capacitave, circuit where \phi approaches \pm \pi/2 , the power can be made arbitrarily small? Even if a resistor were present? Does that mean it wouldn't heat up at all?

V refers to the voltage across the capacitor. It really is a series circuit. The differential equation I wrote is exactly correct for a series RLC (undriven) circuit. The circuit is given in Purcell's textbook, Figure 8.4a on page 303. It is essentially a series RLC with charged capacitor and...

Homework Statement For an overdamped series RLC circuit, determine the coefficients \beta_1 and \beta_2 in the equation V=Ae^{-\beta_1t}+Be^{-\beta_2t} for the case where R=600 \Omega, L=100 \mu H, and C=.01 \mu F. Also determine the ratio of B to A. Homework Equations For a series RLC circuit...