Determination of an unknown frequency (beats)

Principle

Beats occur when two tones have nearly the same frequency. If one frequency is known, then the other frequency can be determined by analysing the beat.

In this experiment, the students determine the frequency of an off-tune tuning fork by the measurement of the beat frequency with the aid of a second tuning fork.

Benefits

• Experiment is part of an experiment set with a total of 22 experiments about generation, propagation and perception of sound, oscillations and waves
• Particularly appropriate as an experiment for first contact with physics in general
• With graphic student worksheets
• With detailed instructor information
• Optimized for tight schedules, i.e. minimum preparation time required

Tasks

Determine the frequency of an off-tune 440 Hz tuning fork. Measure the beat frequency and calculate the possible frequencies of the off-tune tuning fork. Determine whether the frequency of the off-tune tuning fork is higher or lower than the frequency of the tuned tuning fork in order to determine the frequency of the off-tune tuning fork.

Learning objectives

• Beats
• Beat frequency