What change occurs when sound passes from air into water?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. Frequency ramains unchanged, but wavelength varies.
Frequency is a property of the source and remains constant during refraction. Since water is denser than air, the speed of sound increases significantly. To maintain the relationship v= f x Lambda, the wavelength must increase proportionally as the sound enters the water.
Other Options:
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Frequency increases while wavelength stays constant: Incorrect because frequency never changes during medium transition; only speed and wavelength adjust.
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Both frequency and wavelength decrease: Incorrect; frequency is constant, and wavelength actually increases because sound travels faster in water (approx 1500 m/s) than in air (approx 340m/s).
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Speed decreases while frequency increases: Incorrect; sound travels faster in liquids than in gases due to higher elasticity, and frequency remains unchanged.