Resonance

Resonance describes the phenomenon of increased amplitude that occurs when the frequency of a periodically applied force is equal or close to a natural frequency of the system on which it acts. When an oscillating force is applied at a resonant frequency of a dynamic system, the system will oscillate at a higher amplitude than the force is applied. The amplitude of the system is smaller when the same force is applied at other, non-resonant frequencies.

Investigating an electrical circuit with capacitance and with an inductor, using voltage with sinus wave (AC), we may have 2 types of resonance

• Parallel resonance and
• Serial resonance.

Investigating the the two types of this phenomenon, You will find that the serial resonant circuit will show zero impedance, and the parallel resonant part will show an endless great impedance in (ideal) resonant state.
Remember these when you design Your circuits.