An air bubble of diameter $6\,mm$ rises steadily through a solution of density $1750\,kg / m ^3$ at the rate of $0.35\,cm / s$. The co-efficient of viscosity of the solution (neglect density of air) is $..........\,Pas$ (given, $g =10\,ms ^{-2}$)

The terminal velocity of a small sphere of radius $a$ in a viscous liquid is proportional to

A small spherical ball of radius $r$, falling through a viscous medium of negligible density has terminal velocity ' $v$ '. Another ball of the same mass but of radius $2 r$, falling through the same viscous medium will have terminal velocity:

Give two uses of Stoke’s law.

A Spherical ball of radius $1 mm$ and density $10.5 g / cc$ is dropped in glycerine of coefficient of viscosity $9.8$ poise and density $1.5 g / cc$. Viscous force on the ball when it attains constant velocity is $3696 \times 10^{-x} N$. The value of $x$ is $\text { (Given, } g =9.8 m / s ^2 \text { and } \pi=\frac{22}{7} \text { ) }$

A copper ball of radius $'r'$ travels with a uniform speed $'v'$ in a viscous fluid. If the ball is changed with another ball of radius $'2r'$ , then new uniform speed will be