Mechanical properties of fluids practice · Mixed difficulty

At a given place where acceleration due to gravity is $g\mathrm{m}{\mathrm{s}^{ - 2}},$ a sphere of lead of density $d\mathrm{kg}{\mathrm{m}^{ - 3}}$ is gently released in a column of liquid of density $\mathrm{\rho kg}{\mathrm{m}^{ - 3}}$. If $d > \mathrm{\rho },$ the sphere will

A square wire frame of size L is dipped in a liquid. On taking out a membrane is formed. If the surface tension of liquid is T, then the force acting on a frame will be

A liquid drop of diameter D is divided into 27 equal droplets. If the surface tension is T then the change in energy will be

If pressure at half the depth of a lake is equal to $2/3$ pressure at the bottom of the lake then what is depth of the lake

If two ping pong ball are suspended near each other and a fast stream of air is produced within the space of the balls, the balls

Two capillaries of radii ${r_1}$ and${r_2}$, length ${l_1}$ and ${l_2}$ respectively are in series. A liquid of viscosity $\eta$ is flowing through the combination under a pressure difference $p$. What is the rate of volume flow of liquid?

A hollow cylinder of mass $m$ made heavy at its bottom is floating vertically in water. It is tilled from its vertical position through an angle $\theta$ and is left. The restoring force acting on it is

A log of wood of mass $120kg$ floats in water. The weight that can be put on raft to make it just sink, should be (density of wood $= 600kg/{m^3}$)

Streamline flow is more likely for liquid with

27 spherical rain drops of the same mass and radius are falling down with a terminal sped $4\,\,\,cm{s^{ - 1}}.$ If they coalesce to form one big drop, what will be the terminal speed of bigger drop?

[Neglect the buoyancy of the air] $\left[ {{\text{in}}\,\,\,cm{s^{ - 1}}} \right]$

Angle of contact of a liquid with a solid depend on

A liquid is allowed into a tube of truncated cone shape. Identify the correct statement from the following.

Small droplets of liquid are usually more spherical in shape than larger drops of the same liquid because

This question has statement -I and statement-II of the four choices given after the statements. Choose the one that best describes the two statements.
Statement-I: A capillary tube is dipped in a liquid rises to a height $h$ in it. As the temperature of the liquid is raised, the height $h$ decreases (if the density of the liquid and the angle of contact remain the same)
Statement-II: Surface tension of a liquid decreases with the rise in its temperature.

A rain drop of radius $r$ falls in air with terminal velocity $v.$ What is the terminal velocity of a rain drop of radius $3r?$

A cork is submerged in water by a spring attached to the bottom of a bowl. When the bowl is kept in an elevator moving with acceleration downwards, the length of spring

Two metal spheres are falling through a liquid of density $2 \times {10^3}kg/{m^3}$with the same uniform speed. The material density of sphere 1 and sphere 2 are $8 \times {10^3}kg/{m^3}$ and $11 \times {10^3}kg/{m^3}$ respectively. The ratio of their radii is

Determine the energy stored in the surface of a soap bubble of radius 2.1 cm if its surface tension is $4.5 \times {10^{ - 2}}\mathrm{N}{\mathrm{m}^{ - 1}}$

Assertion: The upper surface of the wings of an aeroplane is made convex and the lower surface is made concave.
Reason: The air currents at the top have a smaller velocity and thus less pressure at the bottom than at the top.

Given below are two statements: One is labelled as Assertion (A) and other is labelled as Reason (R).
Assertion (A) : Time period of oscillation of a liquid drop depends on surface tension $(S)$, if density of the liquid is $\rho$ and radius of the drop is $r$, then $T=K \sqrt{\frac{\rho r^3}{S^{3 / 2}}}$ is dimensionally correct, where $K$ is dimensionless.
Reason (R) : Using dimensional analysis we get R.H.S. having different dimension than that of time period.
In the light of above statements, choose the correct answer from the options given below.

The weight of an aeroplane flying in the air is balanced by

A narrow capillary tube when dipped in a beaker containing water the rise in 20 cm . If the area of cross-section of the bore is reduced to 1/4th value water will raise to a height of

Assertion:- Machine parts are jammed in winter.
Reason:-The viscosity of lubricant used in machine part decrease at low temperature.

Two cylindrical vessels with their bases at the same level, contain a liquid of density $\rho$. The height of the liquid in the vessel is ${h_1}$ and in the other is ${h_2}$. The area of either base is A. The work done by the gravity in equalizing the levels when the vessels are connected.

An ice block floats in a liquid whose density is less than water. A part of block is outside the liquid. When whole of ice has melted, the liquid level will

For a ball falling in a liquid with constant velocity, ratio of the resistance force due to the liquid to that due to gravity is

Hair of shaving brush cling together when it is removed from water due to

Eight identical drops of water, each of radius $2 \mathrm{~mm}$ are falling through air at a terminal velocity of $8 \mathrm{~cm} \mathrm{~s}^{-1}.$ If they coalesce to form a single drop, then the terminal velocity of combined drop will be:

Bernoulli’s principle is not involved in the working/explanation of

A drop of water breaks into two droplets of equal size. In this process, which of the following statements is correct?