Physics And Measurement Question 65
Question: A spherical body of mass $ m $ and radius $ r $ is allowed to fall in a medium of viscosity $ \eta $ . The time in which the velocity of the body increases from zero to 0.63 times the terminal velocity $ (v) $ is called time constant $ (\tau ) $ . Dimensionally $ \tau $ can be represented by
[AIIMS 1987]
Options:
A) $ \frac{mr^{2}}{6\pi \eta } $
B) $ \sqrt{( \frac{6\pi mr\eta }{g^{2}} )} $
C) $ \frac{m}{6\pi \eta rv} $
D) None of the above
Show Answer
Answer:
Correct Answer: D
Solution:
Time constant $ \tau =[T] $ and Viscosity $ \eta =[M{{L}^{-1}}{{T}^{-1}}] $
For options and dimensions are not matching with time constant.
