Q. The force $F$ on the sphere of radius ‘$a$’ moving in a medium with velocity $'\upsilon'$ is given by $F = 6\pi\eta a\upsilon$. The dimensions of $\eta$ are
A) $ML^{- 1}T^{- 1}$
B) $MT^{- 1}$
C) $MLT^{- 2}$
D) $ML^{- 3}$
Explanation
$\eta = \frac{F}{av} = \frac{\lbrack MLT^{- 2}\rbrack}{\lbrack L\rbrack\lbrack LT^{- 1}\rbrack} = \lbrack ML^{- 1}T^{- 1}\rbrack$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.