Q. 5 The angle of contact at the interface of the water-glass is 0°, ethyl alcohol-glass is 0°, mercury-glass is 140° and methyliodide-glass is 30°. A glass capillary is put in a trough containing one of these four liquids is observed that the meniscus is convex. The liquid in the trough is:

Q. 6 For a surface molecule,
(a) the net force on it is zero

(b) there is a net downward force

(c) the potential energy is less than that of a molecule inside

(d) the potential energy is more than that of a molecule inside

Q. 8 A wooden block with a coin placed on its top, floats in water as shown in
figure.

The distance l and h are shown in the figure. After some time, the coin falls
into the water. Then,

(a) l decreases

(b) h decreases

(c) l increases

(d) h increases

With an increase in temperature, the viscosity of:
a. gases decreases.
b. liquids increases.
c. gases increases.
d. liquids decreases.

Q. 10 Streamline flow is more likely for liquids with
(a) high density

(b) high viscosity

(c) low density

(d) low viscosity

A liquid does not wet the solid surface if the angle of contact is:

A barometer is constructed using a liquid ( density = $760 \mathrm{kg}/{\mathrm{m}}^3$ ). What would be the height of the liquid column, when a mercury barometer reads 76 cm? 

$(\mathrm{density} \mathrm{of} \mathrm{mercury} = 13600 \mathrm{kg}/{\mathrm{m}}^3)$

The two thigh bones (femurs), each of cross-sectional area $10 {\mathrm{cm}}^2$ support the upper part of a human body of mass 40 kg. The average pressure sustained by the femurs is:

Pressure on a swimmer 10 m below the surface of a lake is:

The density of the atmosphere at sea level is $1.29 {\mathrm{kgm}}^{-3}$. Assume that it does not change with altitude. Then how high would the atmosphere extend?

At a depth of 1000 m in an ocean, the force acting on the window of area 20 cm × 20 cm of a submarine is? The interior of the submarine is maintained at sea-level atmospheric pressure. (The density of sea water is 1.03 × 10³ kg m^-3, g = 10 m s^–2)

Two syringes of different cross-sections (without needles) filled with water are connected with a tightly fitted rubber tube filled with water. Diameters of the smaller piston and larger piston are 1.0 cm and 3.0 cm respectively. Force exerted on the larger piston when a force of 10 N is applied to the smaller piston:

Two syringes of different cross-sections (without needles) filled with water are connected with a tightly fitted rubber tube filled with water. Diameters of the smaller piston and larger piston are 1.0 cm and 3.0 cm respectively. If the smaller piston is pushed in through 6.0 cm, how much does the larger piston move out?

In a car lift, the compressed air exerts a force ${\mathrm{F}}_1$ on a small piston having a radius of 5.0 cm. This pressure is transmitted to the second piston of a radius of 15 cm. If the mass of the car to be lifted is 1350 kg, the pressure necessary to accomplish this task and the force ${\mathrm{F}}_1$, respectively, are?

(g = 9.8 ms^-2)

The flow of blood in a large artery of an anesthetised dog is diverted through a Venturi meter. The wider part of the meter has a cross-sectional area equal to that of the artery. A = 8 ${\mathrm{mm}}^2$. The narrower part has an area a = 4 ${\mathrm{mm}}^2$. The pressure drop in the artery is 24 Pa. What is the speed of the blood in the artery?

(Density of blood = $1.06\times {10}^3 \mathrm{kg} {\mathrm{m}}^{-3}$)

A fully loaded Boeing aircraft has a mass of $3.3\times {10}^5$ kg. Its total wing area is 500 ${\mathrm{m}}^2$. It is in level flight with a speed of 960 km/h. The pressure difference between the lower and upper surfaces of the wings is: [Given: Density of air, ρ = 1.2 ${\mathrm{kgm}}^{-\mathrm{3\; }}$and g = 9.8 m/s²]

A metal block of area $0.10 {\mathrm{m}}^2$ is connected to a 0.010 kg mass via a string that passes over an ideal pulley (considered massless and frictionless), as in the figure below. A liquid film with a thickness of 0.30 mm is placed between the block and the table. When released the block moves to the right with a constant speed of 0.085 m/s. The coefficient of viscosity of the liquid is:

The terminal velocity of a copper ball of radius 2.0 mm falling through a tank of oil at $20 °\mathrm{C}$ is 6.5 $\mathrm{cm}/\mathrm{s}$. The viscosity of the oil at $20 °\mathrm{C}$ is? (Density of oil is $1.5\times {10}^3 \mathrm{kg}/{\mathrm{m}}^3$, the density of copper is $8.9\times {10}^3 {\mathrm{kgm}}^{-3}$) 

The flow rate of water from a tap of diameter 1.25 cm is 0.48 L/min. The coefficient of viscosity of water is ${10}^{-3} \mathrm{Pa} \mathrm{s}$. After some time, the flow rate is increased to 3 L/min. The type of flow initially and after increasing the velocity is:

The lower end of a capillary tube of diameter 2.00 mm is dipped 10.00 cm below the surface of the water in a beaker. The pressure required in the tube in order to blow a hemispherical bubble at its end in water is? The surface tension of water at the temperature of the experiment is $7.3\times {10}^{-2} \mathrm{N}/\mathrm{m}$, atmospheric pressure = $1.01\times {10}^5 \mathrm{Pa}$, the density of water = 1000 $\mathrm{kg} {\mathrm{m}}^{-3}$, g = 10 $\mathrm{m} {\mathrm{s}}^{-2}$.

A fully loaded Boeing aircraft has a mass of $3.3\times {10}^5$ kg. Its total wing area is 500 ${\mathrm{m}}^2$. It is in level flight with a speed of 960 km/h. The fractional increase in the speed of the air on the upper surface of the wing relative to the lower surface 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 $\frac{\mathrm{d}}{2}$, then the viscous force acting on the ball will be: