In a series R-L-C circuit at resonance, the current is:

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Multiple Choice

In a series R-L-C circuit at resonance, the current is:

At resonance in a series R-L-C circuit, the inductive and capacitive reactances cancel each other (ωL = 1/(ωC)), so the circuit's impedance becomes purely resistive and is at its minimum value, essentially Z = R. Since the same current flows through all components in series, this smallest impedance means the current is at its largest possible value for that supply. The circuit then behaves like a pure resistor at that frequency, with the current in phase with the voltage. The other possibilities don’t fit because the current isn’t zero or DC at AC resonance, and it isn’t minimum—the reactive parts cancel, reducing impedance to its lowest, not highest.

At resonance in a series R-L-C circuit, the inductive and capacitive reactances cancel each other (ωL = 1/(ωC)), so the circuit's impedance becomes purely resistive and is at its minimum value, essentially Z = R. Since the same current flows through all components in series, this smallest impedance means the current is at its largest possible value for that supply. The circuit then behaves like a pure resistor at that frequency, with the current in phase with the voltage. The other possibilities don’t fit because the current isn’t zero or DC at AC resonance, and it isn’t minimum—the reactive parts cancel, reducing impedance to its lowest, not highest.

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