The coefficient of viscosity of an ideal fluid is

Viscous drag force depends on ...........

What is viscosity? What is the cause of it?

The flow of water in a river at the banks is slower than at the middle of the river. Explain.

Write one practical use of viscosity.

There is a $1\, mm$ thick layer of glycerine between a flat plate of area $100\, cm^2$ and a big plate. If the coefficient of viscosity of glycerine is $1.0\, kg/(m\cdot s)$,then the force required to move the plate with a velocity of $7\, cm/s$ is $.......\, N$.