A Level Physics Practice Exam

How is the frequency of the nth harmonic expressed?

1. n * wavelength

2. n * amplitude

3. n * fundamental frequency

4. n * speed of sound

The correct answer is: n * fundamental frequency

The frequency of the nth harmonic is correctly expressed as n times the fundamental frequency. In a standing wave system, such as a string fixed at both ends or an air column, the fundamental frequency (also known as the first harmonic) is the lowest frequency at which the system vibrates. The harmonics occur at integer multiples of this fundamental frequency. Therefore, the nth harmonic's frequency is given by the fundamental frequency multiplied by n, which highlights how the harmonics are related to the basic, or fundamental, vibrating mode of the system. The concept ties closely to how harmonics are formed and perceived in various physical systems, such as musical instruments, where the fundamental frequency determines the pitch and the higher harmonics add richness to the sound. Each subsequent harmonic (2nd, 3rd, etc.) contributes to the total sound, but their frequencies directly depend on the fundamental frequency.