How does inductor filters (if it's reactive and has no losses)?

Hi,
My question is as simple as that...
If inductors and capacitors have no losses (not like resisotrs which does loss as heat), how come they are used in filters?
To what form the attenuation turns to? it attenuates range of freq. to what? Heat? No, it's reactive and has no losses.
So, what then...?
Thanks.

Attenuation doesn't necessarily involve losses respectively absorption of energy. It can be achieved by reflecting a signal back to the source. You get perfect attenuation by just unplugging the cable - without any losses. A reactive filter performs frequency dependent reflection.

yuvalkesi said:

To what form the attenuation turns to?

Click to expand...

A strange question. How many "forms" of attenuation do you think there are?

You should know (don't you?) that the reactance of an inductor increases with frequency. So, if an inductor is connected in series with a line carrying a signal, the reactance (the impedance), increases with frequency and higher frequencies are attenuated more than lower ones.

The opposite is true in the case of a capacitor (in series with the signal). Lower frequencies are attenuated more than higher ones.

If an inductor is connected in parallel with a signal source, its reactance, which decreases with frequency, will reduce the lower frequencies.

The opposite is true if a capacitor is in parallel with the signal source. Its decreasing reactance at higher frequencies attenuates those.

Ok,
Thanks.
Syncopator, I know all about reactance which is frequency dependent, but I was looking for more physical-day-life answer and FvM answered that.
Thanks FvM & Syncopator.

this attenuation may be the result of some electrical noise ........... and u can refer to individual datasheets ...... u might get a better answer for ur question.........

Energy gets dissipated in filters.
What happens if one connects an inductance or capacitance across AC!
Of course, there are reflections in a lines whenever the characteristic impedance changes.