Question 84 of 190

For the given figures, choose the correct options:

AThe rms current in circuit (b) can never be larger than that in (a)BThe rms current in figure (a) is always equal to that in figure (b)CThe rms current in circuit (b) can be larger than that in (a)DAt resonance, current in (b) is less than that in (a)

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Answer: (A) The rms current in circuit (b) can never be larger than that in (a)

For the circuit(a), $Z=R=40\Omega$. Hence,
${I}_{rms}=\dfrac{220}{40}=5.5A$

${X}_{L}=2\pi fL=2\pi \times 50\times 50\times {10}^{-3}=15.7\Omega$ and ${X}_{C}=\dfrac{1}{2\pi fC}=\dfrac{1}{2\pi \times 50\times 0.5\times {10}^{-6}}=6369\Omega$
For the circuit(b), $Z=\sqrt{{R}^{2}+{\left({X}_{L}-{X}_{C}\right)}^{2}}\gt 40\Omega$ as
${X}_{L}$ is not equal to ${X}_{C}$. So rms current in (b) can never be larger than (a)

JEE Main Physics practice question on Alternating Current (AC Circuits), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.