Question

The world’s largest organ was completed in 1930 in Atlantic City, New Jersey. Its shortest pipe is 4.5 mm long. If one end of this pipe is closed, what is the number of harmonics created by an ultrasound with a wavelength of 3.5 mm? 

Answer 1

The number of harmonics is

$$n=\frac{4L}{\lambda}=\frac{4·4.5}{3.5}=5.$$