Beat frequency

Definition

Beat frequency is the frequency at which two waves of slightly different frequencies interfere with each other, resulting in a modulation pattern perceived as a periodic variation in amplitude. It is calculated as the absolute difference between the frequencies of the two interfering waves.

5 Must Know Facts For Your Next Test

1. The beat frequency formula is $f_{beat} = |f_1 - f_2|$, where $f_1$ and $f_2$ are the frequencies of the two waves.
2. Beats occur due to constructive and destructive interference between two waves.
3. The phenomenon is often used in tuning musical instruments to match pitches accurately.
4. If two sound waves have frequencies close to each other, the resulting beat frequency will be low, making it easier to hear distinct beats.
5. In physics experiments, beat frequencies can help measure unknown wave frequencies by comparing them with known reference tones.

Review Questions

• How do you calculate beat frequency when given two wave frequencies?
• What causes beats to occur between two sound waves?
• Why are beat frequencies useful in tuning musical instruments?

Related terms

Interference:

When two or more waves overlap and combine to form a new wave pattern.

Constructive Interference:

Occurs when wave crests overlap, resulting in increased amplitude.

Destructive Interference:

Occurs when a crest meets a trough, leading to reduced amplitude or cancellation.