Solved UPSC CDS/OTA Question
A solved UPSC CDS/OTA PYQ — decoded step-by-step.
Solve it the standard way once — then learn the shortcut.
Q · Waves and SoundEasy · 45s
Which of these changes when a sound wave moves from air into water? 57
TopicWaves and Sound
Question Typemultiple choice
DifficultyEasy
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
Frequency remains the same; speed changes → wavelength changes (v = fλ).
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Final Answer: Option B — Wavelength
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