Final answer:
The correct statement about frequency is that it is the number of oscillations per unit time, which affects the pitch of sound and the color of light, but not loudness.
Step-by-step explanation:
The student asked which statement about frequency is true. The correct answer is c) It is the number of oscillations per unit time. Frequency is a fundamental property of waves, and when it comes to sound and light waves, it has specific effects. The frequency of a sound wave affects the pitch we hear but not the loudness; that is determined by amplitude. In the context of light waves, frequency determines the color we perceive. For example, higher frequency light waves are seen as blue, and lower frequency as red.
It's important to clarify misconceptions: Frequency is not inversely proportional to amplitude, nor is it a measure of the loudness of a sound. The loudness of sound is related to its amplitude, where louder sounds have greater amplitudes. On the other hand, pitch is commonly confused with loudness, but it's actually determined by the frequency of the sound wave. These concepts are core principles in the field of physics, particularly within the study of wave behavior.