Advertisements
Advertisements
प्रश्न
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.
उत्तर
The ratio`(omega_0L)/R`is called the quality factor or Q-factor.
`Q = (omega_0L)/R`
The quality factor has high value in receiving circuits in order to get a sharp gain for the desired channel frequency.
The quality factor depends on the values of the following:
-
Inductance
-
Resistance
-
Capacitance
APPEARS IN
संबंधित प्रश्न
When an AC source is connected to an ideal inductor show that the average power supplied by the source over a complete cycle is zero.
Ajit had a high tension tower erected on his farm land. He kept complaining to the authorities to remove it as it was occupying a large portion of his land. His uncle, who was a teacher, explained to him the need for erecting these towers for efficient transmission of power. As Ajit realised its significance, he stopped complaining.
Answer the following questions:
(a) Why is it necessary to transport power at high voltage?
(b) A low power factor implies large power loss. Explain.
(c) Write two values each displayed by Ajit and his uncle.
Prove theoretically the relation between e.m.f. induced in a coil and rate of change of magnetic flux in electromagnetic induction.
An A.C. generator generating an emf of ε = 300 sin (100 πt) V is connected to a series combination of 16μ F capacitor, 1 H inductor and 100 Ω resistor.
Calculate :
1) An impedance of the circuit at the given frequency.
2) Resonant frequency `f_0`
3)Power factor at the resonant frequency `f_0`.
In a circuit, containing a capacitor and an AC source, the current is zero at the instant the source voltage is maximum. Is it consistent with Ohm's Law?
Consider the situation of the previous problem. Find the average electric field energy stored in the capacitor and the average magnetic field energy stored in the coil.
Suppose the circuit has a resistance of 15 Ω. Obtain the average power transferred to each element of the circuit, and the total power absorbed.
The average power dissipation in a pure capacitor in A.C circuit is
Which of the following quantities remains constant in a step-down Transformer?
