Physics And Measurement Question 140
Question: According to Newton, the viscous force acting between liquid layers of area A and velocity gradient $ \Delta v/\Delta z $ is given by $ F=-\eta A\frac{\Delta v}{\Delta z} $ where $ \eta $ is constant called coefficient of viscosity. The dimension of $ \eta $ are?
[JIPMER 2001, 02]
Options:
A) $ [ML^{2}{{T}^{-2}}] $
B) $ [M{{L}^{-1}}{{T}^{-1}}] $
C) $ [M{{L}^{-2}}{{T}^{-2}}] $
D) $ [M^{0}L^{0}T^{0}] $
Show Answer
Answer:
Correct Answer: B
Solution:
$ F=-\eta A\frac{\Delta v}{\Delta z}\Rightarrow [\eta ]=[M{{L}^{-1}}{{T}^{-1}}] $
As $ F=[ML{{T}^{-2}}],A=[L^{2}],\frac{\Delta v}{\Delta z}=[{{T}^{-1}}] $
