A voltage of peak value 283 V and varying frequency is applied to a series L – C – R combination in which $R = 3\;{\rm{\Omega }}$ , $L = 25$ mH and $C = 400\mu {\rm{F}}$ . The frequency (in Hz)of the source at which maximum power is dissipated in the above, is

JEE PHYSICS MCQ: ALTERNATING CURRENT

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A voltage of peak value 283 V and varying frequency is applied to a series L – C – R combination in which

R = 3\;\mathrm{\Omega }

L = 25

mH and

C = 400\mu \mathrm{F}

. The frequency (in Hz)of the source at which maximum power is dissipated in the above, is

View answer and explanation

Correct option: D

50.3

Option D (50.3) is correct because maximum power dissipation occurs at resonance, and the resonant frequency is calculated using the formula v = 1/(2*pi*sqrt(LC)).

More Questions from ALTERNATING CURRENT

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In a series RC circuit with an AC source,

R=300 \, \Omega

C=25 \, \mu \mathrm{F}, \varepsilon_0=50 \mathrm{~V}

and

v=50 / \pi \, \mathrm{Hz}

. Find the peak current and the average power dissipated in the circuit. In a series circuit

R=300 \Omega, L=0.9 \mathrm{~H}, C=2.0

\mu F

and

\omega=1000 \mathrm{~rad} / \mathrm{sec}

. The impedance of the circuit is: An L-C-R series circuit with a resistance of

100 \Omega

is connected to

200 \mathrm{~V}

(AC source) and angular frequency

300 \, \mathrm{rad} / \mathrm{s}

. When only the capacitor is removed, then the current lags behind the voltage by

60^{\circ}

. When only the inductor is removed the current leads the voltage by

60^{\circ}

. The average power dissipated in original L-C-R circuit is Assertion (A) : In series

L-C \cdot R, \mathrm{AC}

circuit, current and voltage are in same phase at resonance.

Reason (R) : In series

L-C-R, \mathrm{AC}

circuit, resonant frequency does not depend on the value of resistance. Hence, current at resonance does not depend on resistance. A series

L-C-R

circuit is connected to an

\mathrm{AC}

voltage source. When

L

is removed from the circuit, the phase difference between current and voltage is

\frac{\pi}{4}

. If instead

C

is removed from the circuit, the phase difference is again

\frac{\pi}{4}

between current and voltage. The power factor of the circuit is A capacitor in an ideal LC circuit is fully charged by a DC source. Then it is disconnected from DC source, the current in the circuit