Standing waves on a string: A guitar string is fixed at both ends. If you tighten it to increase its tension
A) the frequencies of its vibrational modes will increase but its wavelengths will not be affected.
B) the wavelength increases but the frequency is not affected.
C) both the frequency and the wavelength increase.

Question

Quizplus · Accepted Answer

Tightening the string increases its tension, which in turn increases the speed of propagation of the waves on the string. Since the frequency of a standing wave on a string is determined by the speed of propagation and the wavelength, an increase in speed will result in an increase in frequency. However, since the string is fixed at both ends, the wavelength cannot change. Therefore, choice A is the best choice.

Standing Waves on a String: a Guitar String Is Fixed