2024 · Q28
A sound wave having frequency of 300 Hz is travelling in an unknown medium. Its wavelength is not known. It travels a distance equal to 150 times its wavelength in time t. The value of t is:
General KnowledgePhysics
- A0.5 s
- B1 s
- C1.5 s
- D2 s
Explanation
The wave travels 150 wavelengths in time t, so the distance covered is 150λ. Wave speed v equals frequency times wavelength (v = fλ = 300λ). Time equals distance divided by speed: t = 150λ / 300λ = 0.5 seconds, with the unknown wavelength cancelling out. Hence option A is correct.