# Recent content by undergradphys

1. ### Measuring Current Noise Density

I have found a spec analyzer that is rated from 100Hz to 9MHz (might be more on the higher side, my memory is poor) Which is a suitable range for the measurements i am looking to do. How would i measure the Current Noise Density using a spec analyzer? Is there a simple operation? By the way, i...
2. ### Measuring Current Noise Density

What kind of info are you looking for? I am a layman when it come's to this topic. The only thing that is special about this power supply is that it was made to power our system specifically and was constructed to have low noise. The configuration of the power supply is it can be powered by...
3. ### Measuring Current Noise Density

I have a power source that is supposed to be low noise, and i want to verify that the data the company sent me is indeed accurate. In order to do this, i want to reproduce their graph showing current noise density (nA/root(Hz)) on the Y axis, and Hz on the X axis. I am an undergraduate physics...
4. ### Complex integral over a circle

To be honest i can do the problems but the cauchy integral theorem still perplexes me. I understand the integral fails if there is a "hole" within the integral, and equals 0 everywhere else. So i guess what im really trying to integrate is the pole? So the entire point is to find the integral of...
5. ### Complex integral over a circle

Okay so an integral is analytic if it satisfied the cauchy reimann equations. Basically what i know is if an equation satisfies the cauchy reimann equations, all is good and it can be worked with. I need to solve the second order cauchy reimann equation in order to prove a function is harmonic...
6. ### Complex integral over a circle

I know, i am struggling in this class and im trying to keep up with it. I am going to re-read the chapter in order to understand the cauchy integral theorem but to be honest im pretty poor at learning math out of books. I am best at visualizing problems which is particularly difficult in complex...
7. ### Complex integral over a circle

Okay so third times a charm, i figured out that it is not f^(m-1), but f with derivatives equal to m-1. So since my m=1 for this, i do not have to take a derivative but only evaluate it at 3/2 over !0. so my answer is pi * i * 3/2 * e^(3/2)
8. ### Complex integral over a circle

Okay so i have looked abck and tried to understand the derivation again, and have realized it comes as a consquence of the equation integral of f(z)/(z-z0)^m dz is equal to 2pi*i f^(m-1) (z0) / (m-1)! (if anyone finds my notation to be confusing or sloppy, i can rewrite it. also is there a...
9. ### Complex integral over a circle

1. let C be the circle |z| = 2 traveled once in the positive sense. Computer the following integrals... a.∫c zez/(2z-3) dz Homework Equations I am confused as to a step in my solution, but i believe a relevant equation is if i am integrating over a circle and the function is analytic...
10. ### Quantum Optics Lab: Biting off more than I can Chew?

I would suggest you don't, i was the same way and wanted to take advanced courses earlier to jump ahead and really get going with the real "meat" of physics work, and if your looking to go on to grad school later i think its best to slow it down, keep doing the normal stuff and not delve into...
11. ### Normalizing a wave function.

I rechecked the normalization coeffecient, and substituted in my expressions for E1 and E2, (Hbarω and 4hbarω respectively) t get an expression for ψ(x,t). Now the directions said to use eulers formula to simplify and elminate exponentials... soo.... ψ(x,t) = SQRT(1/2)*[ψ1(x)e-iE1t/hbar +...
12. ### Normalizing a wave function.

You can see im quite new (and perhaps not the best) at this? so i am reading and figuring this out as i go and i found that ψ(x,t) = ψ(x)*e-iEt/hbar Since i was given En, i can substitute that in for E in the above equation. yielding: ψ(x,0) = 1/4[ψ1(x)e-iE1t/hbar +...
13. ### Normalizing a wave function.

Okay, so now knowing that A=1/4 i return to my equations... ψ(x,0) = A[ψ1(x) + ψ2(x)] and im looking to find Find ψ(x,t). In order to do this i need to know change my equations for ψ so that they are related to t, time. I am given ω (angular frequency) which i know is related to t. The...
14. ### Normalizing a wave function.

(wrote this before i saw the above response) Maybe i cant evaluate it from 0 to L? Should I be evaluating it from negative infinity to positive infinity (i could then double the integral, and evaluate from 0 to infinity because Sin^2 is a even function) The bad part is we went over this part...
15. ### Normalizing a wave function.

Homework Statement Okay, so i have a wave function from a particle in an infinite square well that has an initiate wave function with an even mixture of the first two stationary states. ψ(x,0) = A[ψ1(x) + ψ2(x)] a. Normalize ψ(x,0) b Find ψ(x,t) and |ψ(x,t)|2 (use Euler's formula...