NEET Physics Mechanical Properties Of Fluids MCQs

Two capillaries of same length but different radii $r_1$ and $r_2$ are connected in series. The pressure difference across the first capillary is $\Delta P_1$ and across the second is $\Delta P_2$. If the rate of flow of liquid through the combination is $Q$, and $r_1 = 2r_2$, then the ratio $\Delta P_1/\Delta P_2$ is:

A liquid flows through a pipe of non-uniform cross-section. If the radius at point A is half the radius at point B, and the velocity at point A is $v$, what is the velocity at point B?

If the pressure difference across a capillary is doubled and the radius is halved, keeping other factors constant, the volume flow rate will become:

Which of the following factors does not directly affect the viscous force acting on a spherical object moving through a viscous fluid according to Stokes' Law?

Two identical capillaries of length 'L' and radius 'r' are connected in parallel. If the pressure difference across each capillary is 'ΔP', and the viscosity of the liquid is 'η', the total volume flow rate through the combination is:

A viscous liquid flows through a horizontal pipe of varying cross-section. At point A, the radius is 'r' and the velocity is 'v'. At point B, the radius is 'r/2'. Ignoring any energy losses due to viscosity, what is the pressure difference between points A and B?

A large open tank filled with an incompressible, non-viscous fluid up to a height 'H' has a small hole at a depth 'h' below the free surface. A second identical tank is filled with the same fluid to the same height 'H', but instead of a hole, it has a short, horizontal, frictionless pipe of cross-sectional area 'a' attached at a depth 'h'. If the cross-sectional area of the hole is also 'a', the ratio of the initial horizontal velocity of the fluid exiting the pipe to the initial horizontal velocity of the fluid exiting the hole is:

A small solid sphere of radius 'r' and density 'ρ' falls under gravity in a viscous fluid of density 'σ' and coefficient of viscosity 'η'. If $\rho > \sigma$, and the sphere has attained terminal velocity, which of the following changes would result in a decrease in the terminal velocity, assuming all other factors remain constant?

Two identical spheres, A and B, are released simultaneously from the same height in two different viscous liquids. Sphere A reaches terminal velocity faster than sphere B. Which of the following conclusions can be drawn about the liquids?

A raindrop of radius 'r' falls through air with a terminal velocity 'v'. If two such raindrops coalesce to form a larger spherical drop, what will be the new terminal velocity?