Subelement D: Circuits— Topic 29: R-L-C Circuits
Question 3-29D5
Element 3 (GROL)What is the characteristic of the current flow within the parallel elements in a parallel R-L-C circuit at resonance?
Explanation
At parallel resonance, the inductive reactance ($X_L$) equals the capacitive reactance ($X_C$). While this equality causes the overall impedance of the parallel R-L-C circuit to be very high, leading to *minimum current drawn from the source*, it simultaneously facilitates maximum energy exchange between the inductor and the capacitor.
This energy oscillates back and forth between the magnetic field of the inductor and the electric field of the capacitor. This internal, oscillating "circulating current" within the parallel L-C elements becomes very large, often significantly greater than the current supplied by the source. The circuit effectively stores and re-circulates energy, causing the current flow *within* these reactive elements to be maximum.
Options A (Minimum) applies to the current drawn *from the source*, not the internal circulating current. Option C (DC) is incorrect as resonance is an AC phenomenon. Option D (Zero) is incorrect as there is active energy transfer.
Related Questions
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