Mechanical properties of fluids practice · Mixed difficulty

Given below are two statements:

Statement I: If a capillary tube is immersed first in cold water and then in hot water, the height of capillary rise will be smaller in hot water.

Statement II: If a capillary tube is immersed first in cold water and then in hot water, the height of capillary rise will be smaller in cold water.

In the light of the above statements, choose the most appropriate from the options given below

An air bubble of radius $2.0 \mathrm{~mm}$ is formed at the bottom of a $3.3 \mathrm{~m}$ deep river. Calculate the radius of the bubble as it comes to the surface. Atmospheric pressure $=1.0 \times 10^5 \mathrm{~Pa}$ and density of water $=1000 \mathrm{~kg} \mathrm{~m}^{-3}$.

A water film is made between two straight parallel wires of length 10 cm separated by 5 mm from each other. If the distance between the wires is increased by 2 mm. How much work will be done? Surface tension for water is $72\mathrm{dyne c}{\mathrm{m}^{ - 1}}$

The gauge pressure of water in a tank at its bottom is $3.92 \times 10^5 \, {~Pa}$. If the density of water is $1000\, {~kg} / {m}^3$, then the water emerges from the orifice at bottom in the tank with velocity

Assertion:- Smaller drops of liquid resist deforming forces better than the larger drops.
Reason:- Excess pressure inside a drop is directly proportional to its surface area.

Assertion(A): A solid sphere and a hollow sphere both of same material are immersed in a liquid, then change in weight in both the spheres will be same.

Reason(R): Upthrust depends upon the volume of the solid immersed not the mass.

Assertion: Hydrostatic pressure is not a vector quantity.
Reason: Pressure is force divided by area, and force is a vector quantity.

The fraction of a floating object of volume ${V_0}$ and density ${d_0}$ above the surface of a liquid of density $d$ will be

Formation of lead shots use the property of:

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

Bunsen's burner works on the principle of:

Water from a tap emerges vertically downwards with initial velocity $4 \mathrm{~ms}^{-1}$. The cross-sectional area of the tap is $A$. The flow is steady and pressure is constant throughout the stream of water. The distance $h$ vertically below the tap, where the cross-sectional area of the stream becomes $(2 / 3) A$, is (Take, $g=10 \mathrm{~m} \mathrm{~s}^{-2}$ )

A: Kerosene Oil spreads out over water surface
R: Surface tension is a surface phenomenon

The viscous force on a lead shot travelling down with velocity V in a liquid column is F. If the same lead shot travelling down with velocity 3V in an other vertical liquid column is opposed by viscous force 2F, the ratio of the coefficients of viscosities of the liquids is

A good lubricant should have

The excess pressure in a bubble of radius R of a gas in a liquid of surface tension S is

Water rises to a height of $9 \mathrm{~cm}$ in a certain capillary tube. If in the same tube, level of ${Hg}$ is depressed by $3 \mathrm{~cm}$, compare the surface tension of water and mercury. Specific gravity of ${Hg}$ is $13.6,$ the angle of contact for water is zero and that for ${Hg}$ is $135^{\circ}$.

The density of ice is $x \mathrm{~g} \mathrm{~cm}^{-3}$ and that of water is $y \mathrm{~g} \mathrm{~cm}^{-3}$. When $m$ gram of ice melts, then the change in volume is

An aeroplane of mass $3 \times {10^4}$ kg and total wing area of $120{\mathrm{m}^2}$ is in a level flight at some height. The difference in pressure between the upper and lower surface of its wings in kilo pascals is $\left( {\mathrm{g} = 10\mathrm{m}{\mathrm{s}^{ - 2}}} \right)$

An aluminium sphere is dipped into water. Which of the following is true?

Water is flowing through two horizontal pipes of different diameters which are connected together. The diameters of the two pipes are $3 \mathrm{~cm}$ and $6 \mathrm{~cm}$, respectively. If the speed of water in the narrower tube is $4 \mathrm{~ms}^{-1}$, then the speed of water in the wider tube is

When a cylindrical tube is dipped vertically into a liquid the angle of contact is ${140^\mathrm{o}}$, when the tube is dipped with an in inclination of ${40^ \circ }$ the angle of contact is

A closed vessel is half-filled with water. There is a hole near the top of the vessel and air is pumped out from this hole

Express standard atmospheric pressure in bars.

A: A large soap bubble expands while a small bubble shrinks, when they are connected to each other by a capillary tube
R: The excess pressure inside bubble (or drop) is inversely proportional to the radius

Bernoulli's equation is based on the principle of

The amount of work done in increasing size of soap film $6 \mathrm{~cm} \times 4 \mathrm{~cm}$ to $12 \mathrm{~cm} \times 8 \mathrm{~cm}$ is: (surface tension $30 \mathrm{~dyne}/ \mathrm{cm}$)

If two soap bubble of different radii are connected by a tube

A block of ice in which a piece of stone is embedded is floating on water contained in a beaker. When all the ice melts, the level of water in the beaker

The coefficient of viscosity of a liquid does not depend upon: