Recent content by Learnphysics

I'm just trying to get my head around electromagnetics for the first time, and need help understanding a question that asks: "Using BH curves find the maximum permeability of the cast iron forming the magnetic path." Now from wikipedia I know that the permeability of cast iron should be...

My apologies, I've left an exam to the last moment and am trying to cram these things. Our transfer function is: (1+jw/w1)/((1+jw/w2)(1+jw/w2)) I know that when we cascade circuits together we multiply their transfer functions out. The transfer functions of the left op-amp provided...

True, but how does that manifest itself in terms of circuit topology? How can we find out what that transfer function will end up looking like in terms of resistors and capacitors and so on.?

These references, especially the second one help a lot. How do I go from the standard form of H(s).. into the circuit diagram which produces it? Is there any easy technique, or do I need to intuitively familiarize myself to know that a capacitor in parralell with a resistor in the feedback...

Would it simply be the current running through the 0.5 Ohm resistor? I'm not sure what exactly would happen with the inductor resisting changes to the current flowing through it. Would there even be a sudden change? The capacitor will charge to 10V. So that when the switch opens, there will...

Homework Statement http://imgur.com/Mwin7dB http://imgur.com/Mwin7dB Homework Equations The Attempt at a Solution This is a fairly simple problem. My issue is that I can't identify the second initial condition. The first one is simple. At t=0, the voltage on the capacitor is...

Neither one will give you it? My intuition I don't think is strong enough just yet to make that call. I did the math, and following Nascant's advice. Got a transfer function in decibels. Put it into excel (the circuit on the right). I seem to be able to produce a bode plot that is flat until...

I don't believe I've made an error elsewhere. (The working out is up there, if you have time to double check). Instead I think the units are correct because it factorizes into: JWR2(C1+C2). SO the units would be radiens*Ohms*Farads. Same as the denominator. So my gain equation looks like...

It's kind of coming together in my mind. So, in my working out, just before the last 3 lines I have it in (...) / ( 1 + j(ω/ωo) form. with W0 being (1/(R2*C2))Fair enough. What about the numerator. It's got some term "C1", which doens't appear at all in the denominator. The denominator terms...

Homework Statement http://imgur.com/tJEPgbA http://imgur.com/tJEPgbA Homework Equations The Attempt at a Solution I started by focusing on the left Op-amp provided. My methodology to solve this question was essentially to assume a virtual short circuit so that the negative...

Oh right, No idea how I ended up with -74. Thanks guys, this helped out a lot.

Hmm? Does this mean I've done something wrong with my phase angle on the thevenin resistance? How are you reaching -15.945?

http://imgur.com/ExHKGB0 Here's my working, where have I gone wrong. A bit of an explanation of what I've done is basically considering a supernode across the dependent source, and then performing KCL on that node. Relating V1 and V2, then solving for V1. solving for V2, and declaring...

I see..Say that I wanted to solve this by finding Voc/Isc.. When I short the two ports. It makes one side of the dependent voltage source = 0 (directly connected to ground)... So how does that work? If the equation governing the top of the capacitor and the other side of the dependent source is...

I would solve for the output voltage by frequency domain analysis right?