Beat frequency

Definition

Beat frequency is the periodic variation in amplitude observed when two waves of slightly different frequencies interfere with each other. It is equal to the absolute difference between the frequencies of the two combining waves.

5 Must Know Facts For Your Next Test

1. Beat frequency can be calculated using the formula $f_{beat} = |f_1 - f_2|$ where $f_1$ and $f_2$ are the frequencies of the two interfering waves.
2. The phenomenon of beats is often used in musical tuning to identify slight differences in pitch.
3. The beat frequency is heard as a modulation in volume rather than a separate tone.
4. When two sound waves have very close frequencies, their superposition results in alternating constructive and destructive interference, creating beats.
5. The concept of beat frequency also applies to electromagnetic waves, including radio and light waves.

Review Questions

• How do you calculate beat frequency when given two different sound frequencies?
• What physical phenomenon causes beats to occur?
• In what practical application might you use knowledge of beat frequency?

Related terms

Interference:

The process by which two or more waves overlap and combine to form a new wave pattern.

Frequency:

The number of oscillations or cycles per unit time, typically measured in Hertz (Hz).

Amplitude:

The maximum extent of a vibration or displacement from the equilibrium position.