Advertisements
Advertisements
प्रश्न
The selectivity of a series LCR a.c. circuit is large, when ______.
विकल्प
L is large and R is large.
L is small and R is small.
L is large and R is small.
L = R
Advertisements
उत्तर
The selectivity of a series LCR a.c. circuit is large, when L is large and R is small.
Explanation:
Selectivity of a circuit depends on the quality of resonance. The quality factor is given by:
Q = `(w_0 L)/R`
A high value of the quality factor ensures that the resonance curve is sharp. The sharper the resonance curve, the more selective the LCR circuit is. Thus, the selectivity of the LCR circuit is large when L is large and R is small. Hence, the L is large, and R is small.
संबंधित प्रश्न
Define 'quality factor' of resonance in a series LCR circuit. What is its SI unit?
Two coils A and B have inductances 1.0 H and 2.0 H respectively. The resistance of each coil is 10 Ω. Each coil is connected to an ideal battery of emf 2.0 V at t = 0. Let iA and iBbe the currents in the two circuit at time t. Find the ratio iA / iB at (a) t = 100 ms, (b) t = 200 ms and (c) t = 1 s.
A constant current exists in an inductor-coil connected to a battery. The coil is short-circuited and the battery is removed. Show that the charge flown through the coil after the short-circuiting is the same as that which flows in one time constant before the short-circuiting.
Answer the following question.
Draw the diagram of a device that is used to decrease high ac voltage into a low ac voltage and state its working principle. Write four sources of energy loss in this device.
A series LCR circuit containing 5.0 H inductor, 80 µF capacitor and 40 Ω resistor is connected to 230 V variable frequency ac source. The angular frequencies of the source at which power transferred to the circuit is half the power at the resonant angular frequency are likely to be ______.
To reduce the resonant frequency in an LCR series circuit with a generator ______.
A coil of 0.01 henry inductance and 1 ohm resistance is connected to 200 volt, 50 Hz ac supply. Find the impedance of the circuit and time lag between max. alternating voltage and current.
In the given circuit, rms value of current (Irms) through the resistor R is:
When a capacitor is connected in series LR circuit, the alternating current flowing in the circuit ______
