Question

Is it possible for the voltage amplitude across the inductor in a series RLC circuit to exceed the voltage amplitude of the voltage supply? Why or why not?

Short answer

Answer: No, the voltage amplitude across the inductor (VL) of a series RLC circuit cannot exceed the voltage amplitude of the voltage supply (Vs). The supplied voltage will always be equal to the sum of the voltages across the resistor, inductor, and capacitor, and it must be distributed between these components. Therefore, VL cannot be greater than Vs.

Step-by-step solution

Recall the Relationship between Voltages

A series RLC circuit has three components: a resistor (R), an inductor (L), and a capacitor (C). The voltage across each component must add up to the total supplied voltage (Vs) in a series circuit. In other words, Vs = VR + VL + VC where VR is the voltage across the resistor, VL is the voltage across the inductor, and VC is the voltage across the capacitor.

Consider the Resonance Condition

The voltage across the inductor and capacitor is related to the frequency of the AC source. When the circuit is at resonance, the capacitive reactance (XC) and inductive reactance (XL) are equal: XC = XL Remember that voltage across the capacitor (VC) = IX_C and voltage across the inductor (VL) = IX_L. At resonance, the voltages across the inductor and capacitor are equal in magnitude, but they differ in phase by 180 degrees. This means that the voltages across the inductor and capacitor cancel each other out, and the total voltage in the circuit becomes: Vs = VR

Determine if VL can be Greater than Vs

Since the voltage across the inductor and capacitor cancel each other out at resonance, we can conclude that the voltage across the inductor (VL) cannot exceed the voltage supply (Vs). The supplied voltage will always be equal to the sum of the voltages across the resistor, inductor, and capacitor, and it must be distributed between these components. Therefore, VL cannot be greater than Vs. So, it is not possible for the voltage amplitude across the inductor in a series RLC circuit to exceed the voltage amplitude of the voltage supply.