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 & Comparison between Self Inductance and Inertia etc.

Important Questions on LC Oscillations

EASY
IMPORTANT

An oscillating LC circuit consists of a 75 mH inductor and a 1.2 µF capacitor. If the maximum charge to the capacitor is 2.7 µC. The maximum current in the circuit will be _______ mA.

MEDIUM
IMPORTANT

In an LC oscillating circuit with L=75 mH and C=30 μF, the maximum charge of capacitor is 2.7×10-4 C. Maximum current through the circuit will be

HARD
IMPORTANT

In the circuit shown in figure S1 is open and, S2 and S3 are closed. The circuit is in steady state. At time t=0, switch S1, is closed and S2 and S3 are opened simultaneously. V=100 V, R=10 Ω, C=100 μF, L=0.03 H

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Find the maximum charge that will appear on the capacitor at any time

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IMPORTANT

A capacitor of capacitance 0.6 μF is charged by a 6 V battery. Charged capacitor is now connected to an inductor of inductance 2 mH. Then find the current in the circuit when one third energy stored in capacitor converts into the energy stored in inductor.

EASY
IMPORTANT

In L.C oscillation, maximum current in the inductor can be I. If at any instant, electric energy and magnetic energy associated with circuit is equal, then current in the inductor at that instant is

MEDIUM
IMPORTANT

In an L-C oscillation maximum charge on capacitor can be Q0. If at any instant electrical energy is 34th of the magnetic energy then the charge on capacitor at that instant is

EASY
IMPORTANT

When current in coil changes from 5 A to 2 A in 0.1 s, an average of 50 V is produced. The self-inductance in HenryH of the coil is n3. Write the value of n.

EASY
IMPORTANT

A 60μF capacitor is charged to 100 volts. This charged capacitor is connected across a 1.5mH coil, so that LC oscillations occur. The maximum current in the coil is:-

MEDIUM
IMPORTANT

In an LC circuit shown in figure, C=2 F and L=2 H. At time t=0, charge on the capacitor is 3 coulomb and it is decreasing with rate of 4 C s-1. Then choose the correct statement.

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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

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IMPORTANT

A 1.5μF capacitor is charged to 60V and a15mH coil is connected across it. Assuming that the circuit contains no resistance, what will be the maximum current in the coil?

EASY
IMPORTANT

A capacitor of capacitance 100 μF is charged to a potential of 12 V and connected to a 6.4 mH inductor to produce oscillations. The maximum current in the circuit would be :

EASY
IMPORTANT

A capacitor of capacitance 100 μF is charged to a potential of 12 V and is connected to an inductor of inductance 6.4 mH. What is the maximum current through the inductor at resonance?

MEDIUM
IMPORTANT

A 1.5 μF capacitor is charged to 60 V. The charging battery is then disconnected and a 15 mH coil is connected in series with the capacitor so that LC oscillations occur. Assuming that the circuit contains no resistance, the maximum current in this coil shall be close 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 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)