Question
Sun February 27, 2011 By: Jaspreet Singh

define quality factor in an A.C. circuit.why should the quality factor have high value in recieving circuits? name the factors on which it depends?

Expert Reply
Sun February 27, 2011
Dear studnent,
 
 quality factor or Q factor is a dimensionless parameter that describes how underdamped an oscillator or resonator is.Higher Q indicates a lower rate of energy loss relative to the stored energy of the oscillator; the oscillations die out more slowly.A pendulum suspended from a high-quality bearing, oscillating in air, has a high Q, while a pendulum immersed in oil has a low one. 
 
For the receiving circuits, the sensitivity must be high. So, the Q factor must be high.
 
The Q factor (quality factor) of a resonator is a measure of the strength of the damping of its oscillations, or for the relative linewidth.
 
 
The Q factor of a resonator depends on the optical frequency Î½0, the fractional power loss lper round trip, and the round-trip time Trt:
 
Hope this helps.
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