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Homework Statement
The figure shows a simple FM antenna circuit in which L = 8.22 µH and C is variable (the capacitor can be tuned to receive a specific station). The radio signal from your favorite FM station produces a sinusoidal time-varying emf with an amplitude of 12.2 µV and a frequency of 88.3 MHz in the antenna.
(a) To what value, C0 ,should you tune the capacitor in order to best receive this station?
(b) Another radio station's signal produces a sinusoidal time-varying emf with the same amplitude, 12.2 µV, but with a frequency of 88.1 MHz in the antenna. With the circuit tuned to optimize reception at 88.3 MHz, what should the value, R0, of the resistance be in order to reduce by a factor of 2 (compared to the current if the circuit were optimized for 88.1 MHz) the current produced by the signal from this station? (When entering units, use ohm for Ω.)
Homework Equations
Im = Vm[itex]/[/itex][(R)2+(ωL-1/ωC)2](1/2)
The Attempt at a Solution
Part (a) was no problem for me. The answer is 3.95E-13.
Part (b) has me stumped. I don't know what "circuit tuned to optimize reception at 88.3 MHz" means. I assumed that, in an optimized circuit, (ωL-1/ωC) would = 0.
It has to be twice the current in the non-optimized circuit.
IO = 2Im
IO = Vm/R (Because I assumed that ωL-1/ωC = 0, the equation simplifies to Ohm's Law).
If I set this equal to 2Vm[itex]/[/itex][(R)2+(ωL-1/ωC)2](1/2) (or, 2Im) things cancel and I lose my Resistance variable. This leads me to believe that my initial assumption as to the meaning of optimized circuit is wrong. I don't know where to proceed from here.