Balbharati solutions for फिजिक्स [अंग्रेजी] कक्षा ११ महाराष्ट्र राज्य बोर्ड chapter 2 - Mechanical Properties of Fluids [Latest edition]

How important are fluids in our life?

What is meant by atmospheric pressure?

Do you feel excess pressure while swimming under water? Why?

Why does a knife have a sharp edge, and a needle has a sharp tip?

A student of mass 50 kg is standing on both feet. Estimate the pressure exerted by the student on the Earth. Assume reasonable value to any other quantity you need. Justify your assumption. You may use g = 10 m s⁻². By what factor will it change if the student lies on back?

The figures show three containers filled with the same oil. How will the pressures at the bottom compare?

Blow air in to a flat balloon using a cycle pump. Discuss how Pascal’s principle is applicable here.

What will be the normal atmospheric pressure in bar and also in torr?

You must have blown soap bubbles in your childhood. What is their shape?

Why does a greased razor blade float on the surface of water?

Why can a water spider walk comfortably on the surface of still water?

Why are free liquid drops and bubbles always spherical in shape?

Prove that, equivalent S.I. unit of surface tension is J/m².

When we observe the level of water in a capiilary, we note down the level of the tangent to the meniscus inside the water.

When we observe the level of mercury in a capillary we note down the level of the tangent to the meniscus above the mercury column.

How does a water proofing agent work?

What would happen if two streamlines intersect?

Identify some examples of streamline flow and turbulent flow in every day life. How would you explain them? When would your prefer a stream line flow?

CGS unit of viscosity is Poise. Find the relation between Poise and the SI umt of viscosity.

A water pipe with diameter of 5.0 cm is connected to another pipe of diameter 2.5 cm. How would the speeds of the water flow compare?

How does an aeroplane take off?

Why do racer cars and birds have typical shape?

Have you experienced a sideways jerk while driving a two wheeler when a heavy vehicle overtakes you?

Why does dust get deposited only on one side of the blades of a fan?

Why helmets have specific shape?

Does the Bernoulli’s equation change when the fluid is at rest? How?

Observe the shape of blades of a fan and discuss the nature of the air flow when fan is switched on.

Multiple Choice Question.

A hydraulic lift is designed to lift heavy objects of maximum mass 2000 kg. The area of cross-section of piston carrying the load is 2.25 × 10^-2 m². What is the maximum pressure the smaller piston would have to bear?

Two capillary tubes of radii 0.3 cm and 0.6 cm are dipped in the same liquid. The ratio of heights through which the liquid will rise in the tubes is ______.

The energy stored in a soap bubble of diameter 6 cm and T = 0.04 N/m is nearly ______.

Multiple Choice Question.

Two hailstones with radii in the ratio of 1:4 fall from a great height through the atmosphere. Then the ratio of their terminal velocities is

In Bernoulli’s theorem, which of the following is conserved?

Why is the surface tension of paints and lubricating oils kept low?

How much amount of work is done in forming a soap bubble of radius r?

What is the basis of Bernoulli’s principle?

Why is a low-density liquid used as a manometric liquid in a physics laboratory?

What is an incompressible fluid?

Why two or more mercury drops form a single drop when brought in contact with each other?

Why does velocity increase when water flowing in broader pipe enters a narrow pipe?

Why does the speed of a liquid increase and its pressure decrease when a liquid passes through a constriction in a horizontal pipe?

Derive an expression for excess pressure inside a drop of liquid.

Obtain an expression for conservation of mass starting from the equation of continuity.

Explain the capillary action.

Derive an expression for capillary rise for a liquid having a concave meniscus.

Find the pressure 200m below the surface of the ocean if pressure on the free surface of liquid is one atmosphere. (Density of seawater = 1060 kg/m³)

In a hydraulic lift, the input piston had surface area 30 cm² and the output piston has surface area of 1500 cm². If a force of 25 N is applied to the input piston, calculate weight/force on output piston.

Calculate the viscous force acting on a raindrop of diameter 1 mm, falling with a uniform velocity of 2 m/s through air. The coefficient of viscosity of air is 1.8 × 10^-5 Ns/m².

A horizontal force of 1 N is required to move a metal plate of area 10^-2 m² with a velocity of 2 × 10^-2 m/s, when it rests on a layer of oil 1.5 × 10^-3 m thick. Find the coefficient of viscosity of oil.

With what terminal velocity will an air bubble 0.4 mm in diameter rise in a liquid of viscosity 0.1 Ns/m² and specific gravity 0.9? Density of air is 1.29 kg/m³.

The speed of water is 2m/s through a pipe of internal diameter 10 cm. What should be the internal diameter of the nozzle of the pipe if the speed of the water at nozzle is 4 m/s?

With what velocity does water flow out of an orifice in a tank with gauge pressure 4 × 10⁵ N/m² before the flow starts? Density of water = 1000 kg/m³.

The pressure of water inside a closed pipe is 3 × 10⁵ N/m². This pressure reduces to 2 × 10⁵ N/m² on opening the valve of the pipe. Calculate the speed of water flowing through the pipe. [Density of water = 1000 kg/m³].

Calculate the rise of water inside a clean glass capillary tube of radius 0.1 mm, when immersed in water of surface tension 7 × 10^-2 N/m. The angle of contact between water and glass is zero, the density of water = 1000 kg/m³, g = 9.8 m/s².

An air bubble of radius 0.2 mm is situated just below the water surface. Calculate the gauge pressure. Surface tension of water = 7.2 × 10⁻² N/m.

Twenty-seven droplets of water, each of radius 0.1 mm coalesce into a single drop. Find the change in surface energy. Surface tension of water is 0.072 N/m.

A drop of mercury of radius 0.2 cm is broken into 8 droplets of the same size. Find the work done if the surface tension of mercury is 435.5 dyn/cm.

How much work is required to form a bubble of 2 cm radius from the soap solution having surface tension 0.07 N/m?

A rectangular wireframe of size 2 cm x 2 cm, is dipped in a soap solution and taken out. A soap film is formed, if the size of the film is changed to 3 cm x 3 cm, Calculate the work done in the process. The surface tension of the soap film is 3 x 10^-2 N/m.