LC Oscillations

IMPORTANT

LC Oscillations: Overview

This topic covers concepts, such as, L-C Oscillator Circuit, Comparison of L-C Oscillations with Spring Block Oscillations, Frequency of L-C Oscillator Circuit & Energy in L-C Oscillator etc.

Important Questions on LC Oscillations

EASY
IMPORTANT

The natural frequency of the circuit is (in rad s-1),

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EASY
IMPORTANT

A charged 30 μF capacitor is connected to a 27 mH inductor. The angular frequency of free oscillations of the circuit is

HARD
IMPORTANT

An inductor and two capacitors are connected in the circuit as shown in figure. Initially capacitor A has no charge and capacitor B has CV charge. Assume that the circuit has no resistance at all. At t=0, switch S is closed, then given  LC=2π2×104s2 & CV=100 mC
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MEDIUM
IMPORTANT

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 at which the circuit which is closed be t=0. At what time the energy stored is completely magnetic?

HARD
IMPORTANT

A circuit has a self inductance of 1 henry and carries a current of 2 A. To prevent sparking when the circuit is broken, a capacitor which can withstand 400 volts is used. The least capacitance of the capacitor connected across the switch must be equal to

EASY
IMPORTANT

The natural frequency of an LC circuit is 125 kHz. When the capacitor is totally filled with a dielectric material, the natural frequency decreases by 25 kHz. Dielectric constant of the material is nearly

HARD
IMPORTANT

At a moment t=0, when the charge on capacitor C1 is zero, the switch is closed. If I0 be the current through the inductor at t=0, for  t>0 (initially, C2 is uncharged.)

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MEDIUM
IMPORTANT

The tuning circuit of a radio receiver has a resistance of 50 Ω, an inductor of 10 mH and a variable capacitor. 1 MHz radio wave produces a potential difference of 0.1 mV. The values of the capacitor to produce resonance is (Take π2=10)

MEDIUM
IMPORTANT

An oscillator circuit consists of an inductance of 0.5mH and a capacitor of 20μF. The equivalent frequency of the circuit is nearly

EASY
IMPORTANT

An oscillator circuit consists of the inductance of 0.5 mH and a capacitor of 20 μF. The equivalent frequency of the circuit is nearly

MEDIUM
IMPORTANT

The capacitance in an oscillatory LC circuit is increased by 1%. The change in inductance required to restore its frequency of oscillation is to

MEDIUM
IMPORTANT

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. At what time is the energy stored completely magnetic?

EASY
IMPORTANT

In AC circuit in which inductance and capacitance are joined in series. Current is found to be maximum when the value of inductance is 0.5 H and the value of capacitance is 8 μF. The angular frequency of applied alternating voltage will be

EASY
IMPORTANT

A circuit consists of an inductance of 0.5 mH and a capacitor of 20 μF. The frequency of the LC oscillations is approximately

MEDIUM
IMPORTANT

In a series resonant R-L-C circuit, the voltage across R is 100 V and the value of =1000 Ω . The capacitance of the capacitor is 2×10-6 F; angular frequency of AC is 200 rad s-1. Then the potential difference across the inductance coil is

EASY
IMPORTANT

Let L denote the self-inductance of coil which is in series with a capacitor of capacitance C. Which of the following has the unit second?

MEDIUM
IMPORTANT

The frequency of oscillation of current in the inductor is-

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HARD
IMPORTANT

The natural frequency of an LC circuit is 125000 cycles s-1. Then the capacitor C is replaced by another capacitor with a dielectric medium of dielectric constant K. In this case, the frequency decreases by 25 kHz. The value of K is

HARD
IMPORTANT

The natural frequency of an L-C circuit is 125000 cycles/s. When a dielectric medium of dielectric constant K is introduced between the plates of the capacitor, the frequency decreases by 25 kHz. The value of K is

MEDIUM
IMPORTANT

Choose the wrong statement.