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MHT CET 2020 (16 Oct, Shift 1) · Speed of Waves

Speed of Waves question from MHT CET 2020 (16 Oct, Shift 1)

Q29MHT CET 2020 · 16 OCT · SHIFT 1Medium

Speed of Waves

The extension in a wire obeying Hooke's law is xx. The speed of sound in the stretched wire is vv. If the extension in the wire is increased to 4x4x, then the speed of sound in a wire is

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Answer: (b)

  1. Hooke's law: T∝xT \propto x, and v=T/μ∝xv = \sqrt{T/\mu} \propto \sqrt{x}.
  2. v′=v4x/x=2vv' = v\sqrt{4x/x} = 2v
  3. So the answer is (b) 2v2v.
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