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JEE Main · 2023 · 13 Apr 2023 · Shift 2 · Fluid Mechanics

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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A : A spherical body of radius mm having a particular density is falling through a liquid of constant density. The percentage error in the calculation of its terminal velocity is .
Reason R: The terminal velocity of the spherical body falling through the liquid is inversely proportional to its radius.
In the light of the above statements, choose the correct answer from the options given below
  1. (A)Both and are true but is NOT the correct explanation of
  2. (B)Both and are true and is the correct explanation of
  3. (C) is false but is true
  4. (D) is true but is false✓ Correct

Answer: (D)

Solution

Terminal velocity (from Stokes' law). The fractional error is , so Assertion A is correct. However, Reason R states is inversely proportional to , which is false (it is proportional to ). Thus A is true but R is false.

JEE Main · 2023 · 13 Apr 2023 · Shift 2 · Single correct option

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