What inductance is required with a 17-pF capacitor in order to construct an oscillator capable of generating 550-nm electromagnetic wave. Comment on your answer.

Question

anonymous · Answer

Okay... do you know anything about LC circuits?

anonymous · Answer

No, I did not take the course about electricity first sem. so my background in electricity is a bit weak
I found out this formula for inductance emf=-Ldi/dt but I am not sure if it is helpful

anonymous · Answer

Jeez.  Okay.  Well the physics behind LC circuits is one of the major things you study in an electricity and magnetism course.  What class is this question for?

anonymous · Answer

I am taking an optics course, and it says that electricity and magnetisim is not a prereq.

anonymous · Answer

i just googled lc circuts, is it just a circut with a capacitor and an inductor?

anonymous · Answer

Yes it is, but if you haven't studied Electricity I'd be surprised if you were familiar with what either of those things were.  Regardless, electricity and magnetism really should be a prerequisite for optics, because light is fundamentally an electromagnetic phenomenon, but oh well.  An LC circuit will oscillate with a frequency
$$f = \frac{1}{2\pi \sqrt{LC}} $$
where L and C are the inductance and capacitance, respectively.  You can find the frequency of the electromagnetic wave via the equation
$$f\lambda = c$$
where lambda and c are the wavelength and speed of light.  Just set these things equal to each other and solve for L.

anonymous · Answer

Wow, thanks a lot man. I can see why I was the only one having trouble with this stuff in class. I will talk to the proff. and see if I need to know other things about electricity for the exams. 
Amma also be your fan from now on haha, you know your stuff :D
cya for now :P

anonymous · Answer

Thanks, good luck.