In a medium where velocity is constant, how are wavelength and frequency related?

• A. They are directly proportional.
• B. They are independent.
• C. They are inversely related.
• D. The wavelength equals velocity.

Answer: (C)

In a medium where the wave speed is fixed, the relationship v = f λ holds. Since v is constant, the product f times λ must stay the same, so frequency and wavelength vary inversely: increasing f makes λ decrease in proportion, and vice versa. This is why they are inversely related. If you try to interpret the other options: frequency and wavelength don’t move together (that would be direct proportional), they do influence each other (not independent), and wavelength is not equal to velocity (they are different physical quantities with different units).