Question

The ratio of MKS units and CGS units of coefficient of viscosity is

• A. $\frac{\eta MKS}{\eta CGS}=10$
• B. $\frac{\eta MKS}{\eta CGS}=9.8$
• C. $\frac{\eta MKS}{\eta CGS}=0.1$
• D. $\frac{\eta MKS}{\eta CGS}=\frac{1}{9.8}$

Answer 1

The correct option is A $\frac{\eta MKS}{\eta CGS}=10$

The coefficient of viscosity is the tangential force per unit area required to maintain a unit velocity gradient.
In C.G.S ystem, the unit of coefficient of viscosity is $dynes/c{m}^2$.
In MKS system, the unit of coefficient of viscosity is $N.s/m^2$.
1 N= ${10}^{5}dyne$ and $1m^2={10}^{4}c{m}^2$

$\Rightarrow \frac{{10}^5}{{10}^4}dynes/c{m}^2=10$
Thus, the ratio of $\frac{\eta MKS}{\eta CGS}=10$