AIIMS Physics Mechanical Properties Of Fluids Class 11 Questions

A container of height 10 cm is filled with water. There is a hole at bottom. Find the pressure difference between points A & B:

Find out the work done to expand the soap bubble to radius R = 5 cm (Surface tension of water = 0.1 N/m)

Apply the equation of continuity. A₁V₁ = A₂V₂ 5² × 4 = 2² × V₂ V₂ = 25 Apply the energy equation at both the ends.

Assertion: Sometimes insects can walk on water. Reason: The gravitational force on insect is balanced by force due surface tension.

Consider the following figure.

Water drops stick to the glass surface due to the cohesive forces between them. Water have properties of surface tension that makes them round so that they cover the smallest possible surface area. Hence, both assertion and reason are true but reason is not the correct explanation of assertion.

The formula for the pressure exerted by the liquid on the base is, P = ρgh. Rewrite the above equation. P = (m/V)gh = (m/A×h)gh = gm/A. The force exerted by the liquid is, F = P×A = (gm/A)×A = gm. Since the mass of the A, B and C are equal. Therefore, F_A = F_B = F_C.

A mercury drop of radius 1 cm is sprayed into 10⁶ drops of equal size. The energy expressed in joule is (surface tension of mercury is 460×10⁻³ N/m)

A hydraulic automobile lift is designed to lift cars with a maximum mass of 3000 kg. The area of cross section a of piston carrying the load is 425 cm². What is the maximum pressure would smaller piston have to bear?

If component of velocities of boat relative to river is same normal to river flow (as shown in figure) both boats reach other bank simultaneously.

Water drops take oval shape when falling freely. Surface tension of water is not minimum among all liquids.

The higher the temperature, lower the surface tension and the surface tension of soap solution is less than ordinary water.

Determine the height above the dashed line 'XX' attained by the water stream coming out through the hole is situated at point B in the diagram given below. Given that h= 10 m, l= 2 m and d = 30°.

A needle of length l m and mass m kg is placed horizontally on water surface having surface tension T. Find T in terms of m, l (g is acceleration due to gravity)

A ring of radius R is kept on water surface. Surface tension of water is T and mass is m. What force required lifting the ring from water surface?

Assertion: Surface tension of all lubricating oils and paints is kept high. Reason: Due to high value of surface tension the fluids get damaged.

A body of mass 60 kg is suspended by means of three strings P, Q and R as shown in the figure is in equilibrium. The tension in the string P is

Assertion (A) The stream of water flowing at high speed from a garden hose, pipe tends to spread like a fountain when held vertically up but tends to narrow down when held vertically down. Reason (R) In any steady flow of an incompressible fluid, the volume flow rate of the fluid remains constant.

A spherical body of diameter D is falling in viscous medium. Its terminal velocity is proportional to

Assertion : Surface energy of an oil drop is same whether placed on glass or water surface. Reason : Surface energy is dependent only on the properties of oil.

Assertion: Turbulence is always dissipative. Reason: High reynold number promotes turbulence.

Water is flowing with velocity 4 m s⁻¹ in a cylinder of diameter 8 cm, it is connected to a pipe with it end tip of diameter 2 cm, calculate the velocity of water at this free end.

Pressure head in Bernoulli's equation is

Two spherical soap bubbles of radii a and b in vacuum coalesce under isothermal conditions. The resulting bubbles has a radius given by

A liquid is kept in a cylindrical vessel which is being rotated about a vertical axis through the centre of the circular base. If the radius of the vessel is r and angular velocity of rotation is ω, then the difference in the heights of the liquid at the centre of the vessel and the edge is

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

Which of the following graph depicts spring constant \( k \) versus length \( l \) of the spring correctly?

Neglecting the viscosity of air, the terminal velocity obtained by a raindrop of radius 0.3 mm falling through air of viscosity 1.8 x 10⁻⁵ N s m⁻² will be

Assertion: A needle placed carefully on the surface of water may float, whereas a ball of the same material will always sink. Reason: The buoyancy of an object depends both on the material and shape of the object.

In old age arteries carrying blood in the human body become narrow resulting in an increase in the blood pressure. This follows from

Work of 3.0 × 10⁻⁴ joule is required to be done in increasing the size of a soap film from 10 cm × 6 cm to 10 cm × 11 cm. The surface tension of the film is

If the water falls from a dam into a turbine wheel 19.6 m below, then the velocity of water at the turbines, is (Take g = 9.8 m/s²)

Assertion : Machine parts are jammed in winter. Reason : The viscosity of lubricant used in machine parts increase at low temperatures.

By sucking through a straw, a student can reduce the pressure in his lungs to 750 mm of Hg (density = 13.6 g/cm³). Using the straw, he can drink water from a glass up to a maximum depth of

If a street light of mass M is suspended from the end of a uniform rod of length L in different possible patterns as shown in figure, then

Assertion : A thin stainless steel needle can lay floating on a still water surface. Reason : Any object floats when the buoyancy force balances the weight of the object.

A candle of diameter d is floating on a liquid in a cylindrical container of diameter D (D >> d) as shown in figure. If it is burning at the rate of 2 cm/hour then the top of the candle will

Assertion : Specific gravity of a fluid is a dimensionless quantity. Reason : It is the ratio of density of fluid to the density of water.

Assertion : For Reynold number Rₑ > 2000, the flow of fluid is turbulent. Reason : Inertial forces are dominant compared to the viscous forces at such high Reynold numbers.

A sphere of mass M and radius R is falling in a viscous fluid. The terminal velocity attained by the falling object will be proportional to

In old age arteries carrying blood in the human body become narrow resulting in an increase in the blood pressure. This follows from

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.

Bernoulli's equation is a consequence of conservation of

Two small drops of mercury, each of radius R, coalesce to form a single large drop. The ratio of the total surface energies before and after the change is

A lead shot of 1 mm diameter falls through a long column of glycerine. The variation of its velocity v with distance covered is represented by

Scent sprayer is based on

The property utilized in the manufacture of lead shots is

For liquid to rise in a capillary tube, the angle of contact should be

A column of mercury of length h = 10 cm is contained in the middle of a narrow horizontal tube of length 1 m closed at ends. The air in both halves of the tube is under a pressure of P₀ = 76 cm of mercury. The tube is now slowly made vertical. The distance moved by mercury will be