Mechanical properties of fluids practice · Mixed difficulty

When an air bubble of radius r rises from the bottom to the surface of a lake, its radius becomes $\frac{{5r}}{4}$. Taking the atmospheric pressure to be equal to 10 m height of water column, the depth of the lake would approximately be (ignore the surface tension and the effect of temperature)

Express standard atmospheric pressure in torr.

With increase in temperature, the viscosity of

The level of water in a tank is 5 m high. A hole of area $10\mathrm{c}{\mathrm{m}^2}$ is made in the bottom of the tank. The rate of leakage of water from the hole is

$\mathbf{A}$ : An iron needle placed carefully on the surface of water may float, whereas a solid ball of same material will always sink

$\mathbf{R}$ : The buoyancy on an object depends both on the material and shape of object.

Ice pieces are floating in beaker A containing water also in a beaker B containing miscible liquid of specific gravity 1.2. When ice melts, the level of

An application of Bernoulli’s equation for fluid flow is found in

The rain drops are in spherical shape due to

A small sphere of mass m is dropped from a great height. After it has fallen $100m$, it has attained its terminal velocity and continues to fall at that speed. The work done by air friction against the sphere during the first $100m$ of fall is

A uniform rod is 4 m long and weighs 10 kg. If it is supported on a knife edge at one metre from the end, what weight placed at that end keeps the rod horizontal?

A man is sitting in a boat which is floating in a pond. If the man drink some water from the pond, what will happen to the level of water in the pond?

Why the dam of water reservoir is thick at the bottom

The radius of a soap bubble is increased from $\frac{1}{{\sqrt \pi }}\,cm\,\,to\,\,\frac{2}{{\sqrt \pi }}\,\,cm$. If the surface tension of water is 30 dynes per cm, then the work done will be

The volume of an air bubble becomes three times as it rises from the bottom of a lake to its surface. Assuming atmospheric pressure to be $75cm$of $Hg$and the density of water to be 1/10 of the density of mercury, the depth of the lake is

Two droplets merge with each other and forms a large droplet. In this process

Viscosity is closely related to -

Two capillary tubes of same diameter are put vertically one each in two limbs whose relative densities are 0.8 and 0.6 and surface tension are 60 and 50 dyne/cm respectively. Ratio of heights of liquids in the two tubes is

A water film is formed between two parallel wires of 10 cm length. The distance of 0.5 cm between the wires is increased by 1 mm. Which will be the work done? (Surface tension of water =  $72\mathrm{N}{\mathrm{m}^{ - 1}})$

In the following fig. is shown the flow of liquid through a horizontal pipe. Three tubes $A,B$ and $C$ are connected to the pipe. The radii of the tubes $A,B$ and $C$ at the junction are respectively $2cm,1cm$ and $2cm$. It can be said that the

The working of venturimeter is based on

A piece of wood is floating in water kept in bottle. The bottle is connected to an air pump. Neglect the compressibility of water. When more air is pushed into the bottle from the pump, the piece of wood will float with

The terminal velocity of a ball in air is $v$, where acceleration due to gravity is $g$. Now the same ball is taken in a gravity free space where all other conditions are same. The ball is now pushed at a speed $v v$, then

If the velocity head of a stream of water is equal to 10 cm, then its speed of flow is ($\mathrm{g} = 10\mathrm{m}{\mathrm{s}^{ - 2}}$)

From a steel wire of density ρ is suspended a brass block of density${\rho _B}$. The extension of steel wire comes to $l$. If the brass block is now fully immersed in a liquid of density ${\rho _L}$, the extension becomes $l'$. The ratio $l/l'$ will be

Correct Bernoulli's equation is (symbols have their usual meaning) :

A steel ball is dropped in oil then,

After terminal velocity is reached, the acceleration of a body falling through a fluid is:

Dimensions of coefficient of viscosity are

The water flows from a tap of diameter $1.25cm$ with a rate of $5 \times {10^{ - 5}}{m^3}{s^{ - 1}}$. The density and coefficient of viscosity of water are ${10^3}kg{m^{ - 3}}$ and ${10^{ - 3}}$ Pas, respectively. The flow of water is

Statement – 1: It is difficult to stop bleeding from a cut in the body at high altitude
Statement – 2: The atmospheric pressure at high altitude is lesser than the blood pressure.