Recent content by Matt1234

Homework Statement Silicon at T= 300K contains acceptor atoms at a concentration of Na = 5*10^15 cm-3. Donor atoms are added forming an n-type compensated semiconductor such that the fermi level is 0.215 eV below the conduction band edge. What concentration of donor atoms are added...

Homework Statement Calculate Efi with respect to the center of the bandgap in silicon for t= 200, 400, 600 kelvin. Homework Equations ni = Nc e^-((Ec- Ef)/(kt)) k = Boltzmann constant t= temperature in kelvin Ec = energy level of the conduction band ef= fermi energy level ni=...

if this is not clear i can post more.

Homework Statement [PLAIN]http://img5.imageshack.us/img5/7653/73215327.jpg The answer in the text is sqrt(15)Mg I am not sure how to obtain this from. Please advise.

no longer required sorry. note for those who ever use this thread: d= sqrt ((x2-x1)^2 + (y2-y1)^2)

Attached is the problem and solution for part B, can someone please explain how they obtain the equation for part B, i don't see why they take the root. Thank you. Homework Statement [PLAIN]http://img153.imageshack.us/img153/8149/97578282.jpg

Thank you amok, halls of ivy and unit.

Thank you for your help. So with regards to number 2) the zero solution was included in the original DE that's why I must make it a soln in my final equation? It seems confusing that they state y != 0 in the line where we have dy/y. As far as 1) goes I'm still slightly confused. You...

Homework Statement Hi guys, i need some help with the following: [PLAIN]http://img534.imageshack.us/img534/3079/22742169.jpg I have 2 questions: 1) why do we make it +/- e^c without specifying a domain for x? (this is what i have done in the past for absolute value problems)...

i get it thank you! the observed frequency is higher then the source frequency BUT the frequency you observe while stationary is constant until it passes you. Frequency you observe is dependent of the speed of the source. i wonder what would happen if the source moved faster then the wave...

I think I am making several mistakes, I am not distinguishing between the observed frequency and the actual frequency. I will reread the section. [PLAIN]http://img35.imageshack.us/img35/2637/40068221.png

ok i think i see where i made the mistake: For a stationary source: as the observer moves toward the source with velocity v, the the frequency obsered would increase as well as the intesity. as the observer moves away, the frequency would decrease as well as intensity. for a...

Homework Statement Hi guys can someone clarify something in my text. I have included a screenshot, and marked the area in question. Shouldnt it be that as the point source approaches you the intensity AND frequency increase? (see the pitfall prevention)...

anyone please?

After some more review, R1 must be 2 times greater then Req in order to get that drop arrcoss the load. Req being the equivalent resistance of R2 and 1000 ohms. Now the current being close to 5ma is the next step.