Mechanical Properties of FluidsNEET Physics · Class 11 · NCERT Chapter 9

A certain number of spherical drops of a liquid of radius ‘r’ coalesce to form a single drop of radius ‘R’ and volume ‘V’. If ‘T’ is the surface tension of the liquid, then -

The cylindrical tube of a spray pump has radius R, one end of which has n fine holes, each of radius r. If the speed of the liquid in the tube is V, the speed of the ejection of the liquid through the holes is :

The heart of a man pumps 5 litres of blood through the arteries per minute at a pressure of 150 mm of mercury. If the density of mercury be 13.6×103 kg m3⁄ and g= 10 m s2⁄ then the power of heart in watt is:

If dimensions of critical velocity vc of a liquid flowing through a tube are expressed as [ηxρyrz], where η,ρ and r are the coefficient of viscosity of liquid, density of liquid and radius of the tube respectively, then the values of x, y and z are given by:

Water rises to a height ‘h’ in capillary tube. If the length of capillary tube above the surface of water is made less than ‘h’, then:

Two non-mixing liquids of densities ρ and nρ(n > 1) are put in a container. The height of each liquid is h. A solid cylinder of length L and density d is put in this container. The cylinder floats with its axis vertical and length pL(p < 1) in the denser liquid. The density d is equal to:

A U tube with both ends open to the atmosphere, is partially filled with water. Oil, which is immiscible with water, is poured into one side until it stands at a distance of 10 mm above the water level on the other side. Meanwhile the water rises by 65 mm from its original level (see diagram). The density of the oil is Pa Pa F 10 mm A Oil B E Final water level Initial water level 65 mm C 65 mm Water D

A small sphere of radius ‘r’ falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to

The unit of thermal conductivity is :

Two particles A and B are moving in uniform circular motion in concentric circles of radii r A and r B with equal speed v A and v B respectively. Their time period of rotation is the same. The ratio of angular speed of A to that of B will be :

A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillary tube of radius 2r is immersed in water. The mass of water that will rise in this tube is :

The velocity of a small ball of mass M and density d, when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is d 2 , then the viscous force acting on the ball will be :

A spherical ball is dropped in a long column of a highly viscous liquid. The curve in the graph shown, which represents the speed of the ball (v) as a function of time (t) is

If a soap bubble expands, the pressure inside the bubble

The amount of energy required to form a soap bubble of radius 2 cm from a soap solution is nearly: (surface tension of soap solution = 0.03 N m⁻¹)

The venturi-meter works on :

Consider a water tank shown in the figure. It has one wall at $x=L$ and can be taken to be very wide in the $z$ direction. When filled with a liquid of surface tension $S$ and density $\rho$, the liquid surface makes angle ${\theta }_0$ (${\theta }_0<<1$) with the $x$-axis at $x=L$. If $y(x)$ is the height of the surface then the equation for $y(x)$ is: (take $\theta (x)=\sin \theta (x)=\tan \theta (x)=\frac{dy}{dx}$, $g$ is the acceleration due to gravity)