Question

Quality factor of an LCR circuit does not any unit this statement is correct or wrong?
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Answer 1

Answer:

The quality factor relates the maximum or peak energy stored in the circuit (the reactance) to the energy dissipated (the resistance) during each cycle of oscillation meaning that it is a ratio of resonant frequency to bandwidth and the higher the circuit Q, the smaller the bandwidth, Q = ƒr /BW.

Answer 2

Answer:

As we know the energy stored by capacitor is

2

1

CV

2

and that of by inductor is

2

1

Li

2

. Now at resonance X

L

=X

C

which gives C=ω

2

L.

Now taking the assumption that energy in capacitor = energy stored by inductor, we have

1/2CV

2

=1/2Li

2

ω

2

LV

2

=Li

2

ω

2

V

2

=i

2

⇒ω

2

i

2

Z

2

=i

2

⇒(ωZ)

2

=1⇒(ωR)

2

=1 as Z=R at resonance

So the above result is not true which comes after taking the assumption. So option A is incorrect.

Average power can be written as

P

ag

=VI=I

2

R

Apparent power can be written as P

app

=V

z

I=I

2

Z where Z is impedance which is equal to R at resonance. Hence

P

app

=I

2

R

Hence average power is equal to apparent power.

Explanation:

i hope it will help you.