AC quality factor and transformer

Quality factor and power factor both have the dimensions of

Define quality factor in electrical resonance circuit. Find quality factor of series resonance circuit.

Resonance in ac circuits and transformers

For series LCR circuit,quality factor at resonance will be (symbols have their usual meaning)

Define the quality factor in an a.c. circuit. Why should the quality factor have high value in receiving circuits ? Name the factors on which it depends.

.In a series LCR resonant circuit,the quality factor is measured as "100" .If the inductance is increased by two fold and resistance is decreased by two fold,then the quality factor after this change will be

How can you improve the quality factor of series resonance circuit ?