List of top Physics Questions on Viscosity

A metal block of base area \(0.20 \,m^2\) is placed on a table, as shown in figure. A liquid film of thickness \(0.25\, mm\) is inserted between the block and the table. The block is pushed by a horizontal force of 0.1 N and moves with a constant speed. If the viscosity of the liquid is \(5.0×10^{−3}Pl\), the speed of block is  ________ \(×10^{−3}m/s\)

An air bubble of diameter 6 mm rises steadily through a solution of density 1750kg / m³ at the rate of 0.35 cm/s. The co-efficient of viscosity of the solution (neglect density of air) is ____Pas (given, g = 10ms^-2)

If ρ is the density and η is coefficient of viscosity of fluid which flows with a speed v in the pipe of diameter d, the correct formula for Reynolds number R_e is:

The diameter of an air bubble which was initially 2 mm, rises steadily through a solution of density 1750 kg m^–3 at the rate of 0.35 cms^–1. The coefficient of viscosity of the solution is _______ poise (in nearest integer). (The density of air is negligible).

Water is flowing on a horizontal fixed surface such that its flow velocity varies with \(y\) (vertical direction) as \[ v = k\!\left(\frac{2y^2}{a^2}-\frac{y^3}{a^3}\right). \] If coefficient of viscosity for water is \(\eta\), what will be the shear stress between layers of water at \(y=a\)?

The velocity of water in a river is $18\, km/hr$ near the surface. If the river is $5\, m$ deep, find the shearing stress between the horizontal layers of water. The co-efficient of viscosity of water $= 10^{-2}$ poise.

A large drop of oil (density 0.8 g/cm³ and viscosity \( \eta_0 \)) floats up through a column of another liquid (density 1.2 g/cm³ and viscosity \( \eta_L \)). Assuming that the two liquids do not mix, the velocity with which the oil drop rises will depend on: