A question about Q factor

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Q=Energy stored/Energy dissipated or
Q=Power stored/Power dissipated

in an inductor, the resistance of it is in series with the inductance. we can assume that

Power of inductor=reactance times the current=IX
Power of its resistance=resistance times current=IR

then

Q=Power of inductor/Power of its resistance
Q=IX/IR=X/R

but in a capacitor the leakage resistance is in parallel to its capacitance

Power of capacitor=voltage/reactance=V/X
Power of its resistance=voltage/resistance=V/R

Q=Power of capacitor/Power of its resistance
Q=V/X / V/R=R/X

tell me if it's confusing
 

xulfee said:
it is basicaly quality factor,u can find it for any frequency dependent circuit by ωc/(ωh-ωl),where ωc is center frequency or resonent frequency,ωh is higher stop band & ωl is lower stop band,converse for stop band
Click to expand...

Be careful, not to mix Q factors for different kind of parts resp. circuits.
When you speak of center frequency and stop bands you have something like a bandpass in your mind.
However, a low pass (which also has a Q factor) has neither a center frequency nor a higher stop band. Something similar is true for high pass circuits. Even an all pass with a constant magnitude vs. frequency has a Q factor.
In summary: Q factor cannot be discussed in general - only in relation with specific parts or circuits. Because it´s a matter of definition.
 

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