Introduction to Resonance

Resonance is a phenomenon in which a vibrating system or external force drives another system to oscillate with greater amplitude at specific frequencies. The word Resonance means “to sound” to produce sound when a body produce sound which vibrates with the same sound which vibrates with the same sound wave length of another object.

What is a Resonance?

Resonance in physics is a phenomenon in which an external force or a vibrating system force another system around it to vibrate with greater amplitude at a specified frequency of operation. The frequency at which the second body starts oscillating or vibrating at higher amplitude is called resonant frequency of the body. Resonance can be observed in various musical instruments around us. And also we can say that, Resonance is the phenomenon of setting a body into vibrations by a strong periodic force whose frequency coincides with the natural frequency of the body.

When a person hits, strums or drums or tweaks any instrument, the instrument is set into oscillation at the natural frequency of vibration of the instrument. A unique standing wave pattern defines each frequency of vibration as specific instrument. These natural frequencies of a musical of a musical instrument are known widely as the harmonics of the specified instrument.

If a second interconnected instrument vibrates at that specified frequency then the first object can be forced to vibrate at a frequency higher that its natural frequency. This phenomenon is known as resonance, i.e. one object vibrating or oscillating at the natural frequency of another object forces the other object to vibrate at a frequency higher than its natural frequency.

Examples of Resonance:

  • Microwaves in microwave oven have a frequency equal to the natural frequency of water molecules. The molecules are oscillated and gain kinetic energy raising the temperature and the food.
  • The use of ultrasound to break up gall stones. The frequency of the ultrasound matches the natural frequency causing maximum transfer of energy and the large amplitude of oscillation breaks up the stone.