True or False: Resonance can occur when the frequency of an AC circuit matches the physical length of the circuit.

Resonance in an AC circuit occurs when the frequency of the alternating current matches the natural frequency of the circuit's components, particularly inductors and capacitors. This situation creates a condition where the energy oscillates between the inductive and capacitive elements, resulting in amplified voltage or current at that specific frequency.

When the physical length of the circuit aligns with the wavelength of the AC signal, the circuit may also exhibit resonance characteristics. The alignment enhances the circuit's ability to store and transfer energy effectively, leading to increased amplitude. This phenomenon is commonly observed in antenna design, where the physical length of the antenna is used to resonate with the desired frequency, thus optimizing signal reception and transmission.

The other options are not applicable since resonance specifically pertains to AC circuits and does not occur in DC circuits or only under certain conditions unrelated to frequency matching. Understanding resonance is crucial for designing efficient electrical systems and ensuring proper operation.