Mechanical properties of fluids practice · Mixed difficulty

Streamline flow is more likely for liquid with

Assertion:- Surface tension of water is larger among fluids.
Reason:- There is hydrogen bond in water molecule so its surface tension is larger than other fluids.

A block weighs $15 \mathrm{~N}$ in air. It weighs $12 \mathrm{~N}$ when immersed in water. When immersed in another liquid, it weighs $13 \mathrm{~N}$. Calculate the relative density (specific gravity) of the other liquid.

A raft of wood of mass $120 \mathrm{~kg}$ floats in water. The weight that can be put on the raft to make it just sink, should be (Take, $d_{\text {raft }}=600 \mathrm{kgm}^{-3}$ )

A drop of liquid of diameter 2.8 mm breaks up into 125 identical drops. The change in energy is nearly $\left( {S = 75\,\,\mathrm{dyne}\,\,\mathrm{c}{\mathrm{m}^{ - 1}}} \right)$

The amount of work done in blowing a soap bubble such that its diameter increases from d to $D$ is ($S =$surface tension of solution)

A beaker containing water is balance on the pan of a common balance. A solid of specific gravity 1 and mass 5 g is tied to the arm of the balance and immersed in water contained in the beaker. The scale pan with the beaker

Pressure inside a liquid drop is greater than the pressure outside by an amount $\frac{2 S}{R},$ where $S$ is surface tension of liquid and $R$ is radius of liquid drop. When 8 such identical drops combine together become one single drop than the pressure difference between inside and outside the drop will be

A cubical block of ice floating in water has to support a metal piece weighing $0.5 \mathrm{~kg}$. What can be the minimum edge of the block so that it does not sink in water? Specific gravity of ice $=0.9.$

If the excess pressure inside a liquid drop is 3 times of excess pressure of another liquid drop made from same liquid. Find ratio of their volumes.

The radius R of the soap bubble is doubled under isothermal condition. If T be the surface tension of soap bubble, the work done in doing so is given by

A rain drop of radius 0.3 mm has a terminal velocity in air = 1 m/s. The viscosity of air is $8 \times {10^{ - 5}}$ poise. The viscous force on it is

Statement I: Finer the capillary, greater is the height to
which the liquid rises in the tube.

Statement II: This is in accordance with the ascent
formula.

Due to capillary action, a liquid will rise in a tube. If the angle of contact is

The excess of pressure inside the first soap bubble is $\sqrt{3}$ times that inside the second bubble. The ratio of volume of the first to that the second bubble is

A large tank is filled with water to a height $H$. A small hole is made at the base of the tank. It takes ${T_1}$ time to decrease the height of water to $\frac{H}{\eta }\left( {\eta > 1} \right):$ and it takes ${T_2}$ time to take out the rest of water. If ${T_1} = {T_2}$, then the value of $\eta$ is

When a sphere falling in a viscous fluid attains a terminal velocity, then

A bubble of air 2 mm in diameter rises in a liquid of viscosity 0.075 SI units and density $1350 \mathrm{~kg} \mathrm{~m}^{-3}.$ The terminal velocity of the bubble is about

Out of air and liquid, which substance is more viscous?

Statement A: A small drop of mercury is spherical but bigger drops are oval in shape
Statement B: Surface tension of liquid decreases with increase in temperature.

In which one of the following cases will the liquid flow in a pipe be most streamlined

A cylindrical vessel of $92 \mathrm{~cm}$ height is kept filled upto the rim. It has four holes $1,2,3$ and 4 which are respectively at heights of $20 \mathrm{~cm}, 30 \mathrm{~cm}, 46 \mathrm{~cm}$ and $80 \mathrm{~cm}$ from the horizontal floor. The water falling at the maximum horizontal distance from the vessel comes from

A wooden block is floating in a water tank. The block is pressed to its bottom. During the process, work done is equal to

When cooking oil is heated in a frying pan, the oil moves around in the pan more easily when it is hot. The main reason for this is that with rise in temperature, there is a decrease in:

A glass plate is partly dipped vertically in the mercury and the angle of contact is measured. If the plate is inclined, then the angle of contact will

A vessel filled with water stands on a table. In its side, the vessel has small orifice arranged at a distance 25 cm from the bottom of the vessel and at a distance 16 cm from the level of water which is kept constant. The horizontal distance from the orifice at which the jet of water fall on the table is

Calculate the approximate change in density of water in a lake at a depth of $400 \mathrm{~m}$ below the surface. The density of water at the surface is $1030 \mathrm{~kg} / \mathrm{m}^3$ and bulk modulus of water is $2 \times 10^9 \mathrm{~N} / \mathrm{m}^2$.

A liquid is stirred. When stirring is stopped, the liquid comes to rest due to-

Assertion: Liquids and gases are largely incompressible and densities are therefore, nearly constant at all pressures for liquid only.
Reason: Liquids exhibit a large variation in densities with pressure but gases do not.

If the water pressure gauge shows the pressure at ground floor to be $270 \mathrm{~k} \mathrm{Pa}$, how high would water rise in the pipes of a building?