Advertisements
Advertisements
प्रश्न
To reduce the resonant frequency in an LCR series circuit with a generator ______.
विकल्प
the generator frequency should be reduced.
another capacitor should be added in parallel to the first.
the iron core of the inductor should be removed.
dielectric in the capacitor should be removed.
उत्तर
To reduce the resonant frequency in an LCR series circuit with a generator another capacitor should be added in parallel to the first.
Explanation:
At response XL = XC ⇒ ω0L = `1/(ω_0C)`
⇒ ω0 = `1/sqrt(LC) "rad"/sec`
⇒ v0 = `1/(2pisqrt(LC)) Hz`
Resonant frequency in an L-C-R circuit is given by
`v_0 = 1/(2pisqrt(LC))`
If L or C increases, the resonant frequency will reduce.
To increase capacitance, we must connect another capacitor parallel to the first.
APPEARS IN
संबंधित प्रश्न
In a series LCR circuit connected to an a.c. source of voltage v = vmsinωt, use phasor diagram to derive an expression for the current in the circuit. Hence, obtain the expression for the power dissipated in the circuit. Show that power dissipated at resonance is maximum
An L-R circuit has L = 1.0 H and R = 20 Ω. It is connected across an emf of 2.0 V at t = 0. Find di/dt at (a) t = 100 ms, (b) t = 200 ms and (c) t = 1.0 s.
What will be the potential difference in the circuit when direct current is passed through the circuit?
Use the expression for Lorentz force acting on the charge carriers of a conductor to obtain the expression for the induced emf across the conductor of length l moving with velocity v through a magnetic field B acting perpendicular to its length.
If an LCR series circuit is connected to an ac source, then at resonance the voltage across ______.
Which of the following combinations should be selected for better tuning of an LCR circuit used for communication?
Which of the following statements about a series LCR circuit connected to an ac source is correct?
An alternating voltage of 220 V is applied across a device X. A current of 0.22 A flows in the circuit and it lags behind the applied voltage in phase by π/2 radian. When the same voltage is applied across another device Y, the current in the circuit remains the same and it is in phase with the applied voltage.
- Name the devices X and Y and,
- Calculate the current flowing in the circuit when the same voltage is applied across the series combination of X and Y.
Select the most appropriate option with regard to resonance in a series LCR circuit.
Three students, X, Y and Z performed an experiment for studying the variation of a.c. with frequency in a series LCR circuit and obtained the graphs as shown below. They all used
- an AC source of the same emf and
- inductance of the same value.
- Who used minimum resistance?
- In which case will the quality Q factor be maximum?
- What did the students conclude about the nature of impedance at resonant frequency (f0)?
- An ideal capacitor is connected across 220V, 50Hz, and 220V, 100Hz supplies. Find the ratio of current flowing through it in the two cases.
