MHT CET Medical202621 April 2026Morning ShiftPhysicsWaves and SoundActual
A sound wave travels from a region of air at 20^ C into a region at 40^ C . What is the ratio of the wavelengths ( ₄₀/ ₂₀ ), if the frequency remains constant?
Options
- A313 293
- B313 293
- C40 20
- D40 20
Correct answer
A. 313 293
Step-by-step solution
The speed of sound in an ideal gas is given by v = R T M , which implies v T , where T is the absolute temperature. The absolute temperatures are T₂₀ = 20 + 273 = 293 K and T₄₀ = 40 + 273 = 313 K . Since the frequency f remains constant and v = f , the wavelength is directly proportional to the speed of sound v . Therefore, T . The ratio of the wavelengths is ₄₀ ₂₀ = T₄₀ T₂₀ = 313 293 . Answer: 313 293