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Question
Consider the following statements about sound passing through a gas.
(A) The pressure of the gas at a point oscillates in time.
(B) The position of a small layer of the gas oscillates in time.
Options
Both A and B are correct.
A is correct but B is wrong.
B is correct but A is wrong.
Both A and B are wrong.
Solution
Both A and B are correct.
Sound is a longitudinal wave produced by the oscillation of pressure at a point, thus, forming compressions and rarefactions. That portion of gas itself does not move but the pressure variation causes a disturbance.
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