Advertisements
Advertisements
प्रश्न
Calculate the quality factor of a series LCR circuit with L = 4.0 H, C = 1, μF and R = 20 Ω.
Mention the significance of quality factor in LCR circuit.
उत्तर
The quality factor (Q) of a series LCR circuit is mathematically given as
`Q =1/R sqrt(L/C)`
here
R = resistance = 20Ω
L = inductance = 4.0 H
C = Capacitance = 1μF = 10−6F
So, the quality factor relation can be rewritten as
`Q = 1/20 xx (9/(10^-6))^(1/2)`
or
`Q = 1/20 xx 2 xx 10^3`
So, the quality factor of the given series LCR combination is
`Q=100`
The quality factor is defined as the ratio of voltage drop across the inductor or capacitor to that of applied voltage. It measures the sharpness of resonance of an LCR circuit.
APPEARS IN
संबंधित प्रश्न
In a series LR circuit XL = R and power factor of the circuit is P1. When capacitor with capacitance C such that XL = XC is put in series, the power factor becomes P2. Calculate P1/P2.
Answer in brief.
The total impedance of a circuit decreases when a capacitor is added in series with L and R. Explain why?
Calculate the value of the capacity in picofarad, which will make 101.4 microhenry inductance to oscillate with a frequency of one megahertz.
A charged 10 microfarad capacitor is connected to an 81 mH inductor. What is the angular frequency of free oscillations of the circuit?
When a capacitor connected with coil is completely discharged, then ____________.
Electrical oscillations of desired frequency can be obtained by ______.
The magnetic field energy in an inductor changes from maximum value to minimum value in 10 ms, when connected to an a.c. source. The frequency of the source is ______.
In an oscillating LC circuit, the maximum charge on the capacitor is Q. The charge on the capacitor, when the energy is stored equally between the electric and magnetic field is ____________.
An LC circuit contains a 20 mH inductor and a 50 µF capacitor with an initial charge of 10 mC. The resistance of the circuit is negligible. Let the instant the circuit is closed be t = 0.
(a) What is the total energy stored initially? Is it conserved during LC oscillations?
(b) What is the natural frequency of the circuit?
(c) At what time is the energy stored
(i) completely electrical (i.e., stored in the capacitor)?
(ii) completely magnetic (i.e., stored in the inductor)?
(d) At what times is the total energy shared equally between the inductor and the capacitor?
(e) If a resistor is inserted in the circuit, how much energy is eventually dissipated as heat?
An inductor coil, capacitor, and an A.C. source of rms voltage 24 V are connected in series. When the frequency of the source is varied, a maximum rms current of 6.0 A is observed. If this inductor coil is connected to a battery of emf 12 V and of internal resistance 4Ω, the current will be ______ Amp.
