What do we actually try to do by rotating the knob in the radio for setting a particular station ?
The verb tuning in radio contexts means adjusting the radio receiver to receive the desired radio signal carrier frequency that a particular radio station uses
Then how we are getting a particular radio signal of particular frequency?
This is because of resonance in the circuit--- when you have a bunch of different frequencies driving a resonant system, the response is only strong for those frequencies which are close to the natural frequency of the resonant oscillator.
You can see the same phenomenon in mechanical systems. If you have a mechanical mass on a spring, and you apply a force which varies with time, the amplitude of oscillation is
(F(ω))/(ω^2−ωo^2+iΓ) WhereF(ω)is the Fourier component of the force at the frequencyω,ω0is the natural frequency of the oscillation, andΓis a small damping parameter. In the limit of smallΓ, you pick out only the Fourier component of F near the resonant frequency, those components which are different in frequency cancel because they push and pull at the wrong time given the natural vibration frequency of the oscillator.
This natural Fourier transform property of linear oscillators is the basis of human hearing, where the hairs in the ear are tuned to resonate only very close to one frequency. It is also the basis for radio tuning, or any other linear frequency sensitive response.
The verb tuning in radio contexts means adjusting the radio receiver to receive the desired radio signal carrier frequency that a particular radio station uses
Then how we are getting a particular radio signal of particular frequency?
This is because of resonance in the circuit--- when you have a bunch of different frequencies driving a resonant system, the response is only strong for those frequencies which are close to the natural frequency of the resonant oscillator.
You can see the same phenomenon in mechanical systems. If you have a mechanical mass on a spring, and you apply a force which varies with time, the amplitude of oscillation is
(F(ω))/(ω^2−ωo^2+iΓ)WhereF(ω)is the Fourier component of the force at the frequencyω,ω0is the natural frequency of the oscillation, andΓis a small damping parameter. In the limit of smallΓ, you pick out only the Fourier component of F near the resonant frequency, those components which are different in frequency cancel because they push and pull at the wrong time given the natural vibration frequency of the oscillator.
This natural Fourier transform property of linear oscillators is the basis of human hearing, where the hairs in the ear are tuned to resonate only very close to one frequency. It is also the basis for radio tuning, or any other linear frequency sensitive response.
