Advertisements
Advertisements
प्रश्न
To reduce the resonant frequency in an LCR series circuit with a generator ______.
पर्याय
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.
Advertisements
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
A voltage V = V0 sin ωt is applied to a series LCR circuit. Derive the expression for the average power dissipated over a cycle. Under what condition (i) no power is dissipated even though the current flows through the circuit, (ii) maximum power is dissipated in the circuit?
Why does current in a steady state not flow in a capacitor connected across a battery? However momentary current does flow during charging or discharging of the capacitor. Explain.
The figure shows a series LCR circuit with L = 10.0 H, C = 40 μF, R = 60 Ω connected to a variable frequency 240 V source, calculate
(i) the angular frequency of the source which drives the circuit at resonance,
(ii) the current at the resonating frequency,
(iii) the rms potential drop across the inductor at resonance.
A series LCR circuit is connected to a source having voltage v = vm sin ωt. Derive the expression for the instantaneous current I and its phase relationship to the applied voltage.
Obtain the condition for resonance to occur. Define ‘power factor’. State the conditions under which it is (i) maximum and (ii) minimum.
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.
An LR circuit having a time constant of 50 ms is connected with an ideal battery of emf ε. find the time elapsed before (a) the current reaches half its maximum value, (b) the power dissipated in heat reaches half its maximum value and (c) the magnetic field energy stored in the circuit reaches half its maximum value.
A coil having an inductance L and a resistance R is connected to a battery of emf ε. Find the time taken for the magnetic energy stored in the circuit to change from one fourth of the steady-state value to half of the steady-state value.
Answer the following question.
What is the phase difference between the voltages across the inductor and the capacitor at resonance in the LCR circuit?
Using the phasor diagram, derive the expression for the current flowing in an ideal inductor connected to an a.c. source of voltage, v= vo sin ωt. Hence plot graphs showing the variation of (i) applied voltage and (ii) the current as a function of ωt.
Derive an expression for the average power dissipated in a series LCR circuit.
Choose the correct answer from given options
The phase difference between the current and the voltage in series LCR circuit at resonance is
In an L.C.R. series a.c. circuit, the current ______.
A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is ______.
To reduce the resonant frequency in an LCR series circuit with a generator
The phase diffn b/w the current and voltage at resonance is
Consider the LCR circuit shown in figure. Find the net current i and the phase of i. Show that i = v/Z`. Find the impedance Z for this circuit.
Draw the impedance triangle for a series LCR AC circuit and write the expressions for the impedance and the phase difference between the emf and the current.
A 20Ω resistance, 10 mH inductance coil and 15µF capacitor are joined in series. When a suitable frequency alternating current source is joined to this combination, the circuit resonates. If the resistance is made \[\frac {1}{3}\] rd, the resonant frequency ______.
