1. Nov 14, 2007

### sbe07phy

1. The problem statement, all variables and given/known data
Designing an FM Radio Receiver. You enjoy listening to KONG-FM, which broadcasts at 96.6 MHz. You detest listening to KRUD-FM which broadcasts at 96.5 MHz. You live the same distance from both stations and both transmitters are equally powerful, so both radio signals produce the same 1.0 V source voltage as measured at your house. Your goal is to design an L-C-R radio circuit with the following properties: i) It gives the maximum power response to the signal from KONG-FM; ii) the average power delivered to the resistor in response to KRUD-FM is 1.00% of the average power delivered to KONG-FM. This limits the power received from the unwanted station, making it inaudible. You are required to use an inductor with L = 1.00 µH.

a) Find the capacitance C that satisfies the design requirements?
wrong check mark F
(b) Find the resistance R that satisfies the design requirements?

2. Relevant equations
wL = 1/wC when at max. power and the angle phi = 0 degrees
but i am having trouble with the 1% of the power part of the problem and how to involve that into this.
L = 1.0e-6 H
V = 1.0 V
C?

3. The attempt at a solution
wL=1/wC
C =1/(w^2)L
How do I involve the power into this?
P=IV
Pavg = 0.5*Imax*Vmax*cos(phi)
Pavg = Irms*Vrms*cos(phi)
Pavg = (Irms^2)*R

2. Dec 4, 2007

### quantum_bit

This is a screenshot of the solution from a PDF that I found. I had a little bit of trouble with the same problem.

This helped me figure it out.

Came across this in google, I am probably too late though.

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