Question Detail
Question
A bat emits ultrasonic sound of frequency 100 kHz in air. If this sound meets a water surface, the wavelengths of the reflected and transmitted sound are (Speed of sound in air = 340 m/s and in water = 1500 m/s).
Correct Answer
Option C is the correct answer.
Detailed Explanation
The reflected sound is in air, so λ_air = v_air / f = 340 / 100,000 = 0.0034 m = 3.4 mm. The transmitted sound is in water, so λ_water = v_water / f = 1500 / 100,000 = 0.015 m = 15 mm.
Hint
Wavelength λ = v/f. Frequency remains the same when sound goes from one medium to another.