Matric Part 1/9th Class Physics Chapter 7 Long Question With Answer for Unit 7 Properties of Matter

Question # 1

Define elasticity. explain deforming force, stress, strain and tensile strain.

Ans 1: Elasticity: the property of a body to restore its original shape and size as the deformation force ceases to act is called elasticity.
Ans 2: Deforming force; the applied force that changes shape , length or volume of a substance is called deforming force. In most of the case s, the body returns to its original size and shaper as soon as the deforming force is removed.
Ans 3: Stress: the force acting on a unit area at the surface of a body is called stress
Unit: the S.I unit of stress is newton per square meter(Nm^-2).
It is a scalper quantity
Ans 4: Strain: the ratio between change in object and original object is known as strain. When stress acts on a body, it may change its length , volume, or shape.
Unit: it has no unit due to ration between similar quantities.
Ans 5: Tensile strain: when stress produces a change in the length of an object then the strain is called tensile strain.
Unit: it has no unit as it is simply a ration between two similar quantities.

Question # 2

What are the features of kinetic molecular model of matter? explain the types of matter

Ans 1: Kinetic molecular model: the features of kinetic molecular model of matter is following
1. Matter is made up of particles called molecules
2. The molecules remain in continuous motion
3. Molecules attract each other
Ans 2: Types of matter: the types of matter are following
Solid: solid are very hard . They have fixed shapes and volume. Their molecules are held close together by strong forces of attraction. The vibrate about their mean positions but don not move from place to place.
Example: their examples are stone, metal spoon , pencil etc.
Ans 3: Liquids; the distances between the molecules of a liquid are more than in solids. Thus, attraction forces between them are weaker. They have fixed volume and boiling point. Viscosity and fluidity present in liquids. Their shapes change w.r.t container.
Example: their examples are water, milk , drinks etc
Ans 4: Gases; gases have no fixed shaped and volume. They can be filled in any container of any shape. Their molecules have random motion and high velocities. In gases, molecules are much farther apart than solids or liquids. Gases are lighter than solids and liquids.
Example: their examples are hydrogen, helium, neon, nitrogen etc.
Ans 5: Plasma: when heat is provided to any matter their kinetic energy of molecules increases. They collide to each other , by this collision thy lose their electrons and become positive ions. The mixture of ions, atoms and molecules is called plasma. It is the fourth state of matter. positive ions an electrons get separated in the presence of electric and magnetic fields . It is highly conduction state of matter. it allows electric current to pass through it.
Origin and uses; the most part of the universe is made of plasma. Sun is made of plasma. It exists in neo and fluorescent tubes when they glow.

Question # 3

Define atmospheric pressure . explain it

Ans 1: Atmospheric pressure ; the earth is surrounded by a covered of air called atmosphere. It extends to a few hundred kilometer above sea level. Air is mixture of gases. The density o air in the atmosphere is not uniform. It decrease s continuously as we go up. It acts in all directions
Ans 2: Experiment; take an empty tin can with a lid. Open its cap and put some water in it. Place it over flame. Wait till water begins to boil and the steam expels the air out of the can. Remove it form the flame. Close the can firmly by its cap. Now place the can under tap water. The can will squeeze due to atmospheric pressure.
When the can is cooled by tap water, the steam is it condenses. As the steam changes into water, it leaves an empty space behind it. This lower the pressure inside the can as compared to the atmospheric pressure outside the can. This will cause the can to collapse from all directions. This experiment shows hat atmosphere exerts pressure in all directions. The fact can also be demonstrated by collapsing of an empty plastic bottle when air is sucked out of it.

Question # 4

What is the principle of floatation. explain

Ans 1: Principle of floatation: a floating object displaces a fluid having weight equal to the weight of the object.
Example: an object sinks if its weight is greater than the upthrust acting on it. An object floats if its weight is equal or less than upthrust . When an object floats in a fluid, the upthrust acting on it is equal to the weight of object. In case of floating object, the object equal to the weight of the fluid displaced by the object. This is the principle of floatation. It is applicable on liquid as well as gases.
Ans 2: Applications: the applications of principle of floatation are following
Wooden block: a wooden block floats on water. it is because the weight of an equal volume of water is greater than the weight of the block. According to the principle of flotation. a body floats if it displaces the water equal to the weight of the body when it is partially or completely immersed in water.
Ans 3: Ships and boats: ships and boats are designed on the same principle of flotation. They carry passenger's and goods over water. It would sink in water if its weight including the weight of its passengers s and goods becomes greater than the upthrust of water.

Question # 5

Explain working of hydraulic press on the basis of Pascal's law.

Ans 1: Hydraulic press: hydraulic press works on Pascal's law
Ans 2: Construction and working: it consist of two cylinders of diferent cross sectional areas. Piston A and a are fitted on both cylindrer.
Cross-section ara of small piston a and cross sextion of large piston A force F1 is applied to the small section area a. pressure P is produced by small piston is transmitted equally to large portion and a force F2 act on A which is must larger than F1.
Ans 3: According to Pascal's law: pressure on large piston of ara a will be the same as on smal piston. Since the ration A/a is greater than 1 , so force F2 acting on large piston is greater than F1 acting on small piston
P1=F1/a
P2=F2/A
by comparing
P1=P2
F1/a=F2/A

Question # 6

Explain the application of atmospheric pressure in daily life

Ans 1: Application of atmospheric pressure: the applications of atmospheric pressure in daily life are following
1. The fan in vacuum cleaner lower s air pressure in its bucket. The atmospheric air rushes into it carrying dust and dirt with tit through its intake port. The dust and dirt particles are blocked by the filter while air escapes out.
2. When air is sucked through straw with its other end dipped in a liquid, the air pressure in the straw decrease. this causes the atmospheric pressure to push the liquid up the straw
3. The air pressure inside the bubble and balloon is equal to atmospheric pressure
4. The piston of the syringe is pulled out. This lowers the pressure in the cylinder . The liquid from the bottle enters into the piston through the needle.

Question # 7

State and explain Pascals law

Ans 1: Pascals law: pressure applied at any point of a liquid enclosed in a container, is transmitted without loss to all other parts of liquid
Ans 2: Explanation: consider a glass vessel. By pushing the piston exert force on water . this pressure is transmitted equally throughout the liquids in all directions water comes out of holes in vessel with some force.
Ans 3: Note: Pascals law hold good of fluid, liquid's and gases

Question # 8

Explain how submarine moves up the water surface down into water

Ans 1: Submarines: a submarine can travel over as well as under water. it also work on the principle of floatation. I t floats over water when the weight of water is equal to its volume is greater than its weight. Under this condition , it is similar to a ship and remains partially above water level. It has a system of tanks which can be filed with and emptied from seawater. When these tanks are filed with seawater, the weight of the submarine increases. As son as its weight becomes greater than the upthrust, it dives into water and remains under water . To com up on the surface, the tanks are emptied from sea water.

Question # 9

State and explain Hook's law

Ans 1: Hook's law: the strain produced in a body by the stress applied to it is directly proportional to the stress with in the elastic limit of the body
Ans 2: Explanation; Hook's law is applicable to all kinds of deformation and all type of matter i.e. solids, liquids or gases within certain limit. This limit tells the maximum stress that can be safely applied on a body with out causing permanent deformation in its length volume or shape.
In other words, it is a limit with in which a body recovers its original length, volume or shape after the deforming force is removed. When a stress crosses this limit, called the elastic limit, a body is permanently deformed and is unable to restore its original state after the stress is removed

Question # 10

What is barometer? how atmospheric pressure is measured using a barometer

Ans 1: Barometer; the instrument that measure atmospheric pressure is called barometer.
Ans 2: Construction of barometer; one of the simplest barometer is mercury barometer . It consists of a glass tube 1 m long closed at one end. It is filled with mercury
Ans 3: measurement of atmospheric pressure using a barometer : to measure atmospheric pressure, then after filing with mercury, barometer is invented in a mercury trough. Mercury in the tube descends and stops at a certain height. The column of mercury held in tube exerts pressure at its base. At sea level the height of mercury column above the mercury in the trough is found to be about 76 cm . Pressure exerted by 76 cm of mercury column is nearly 101300Nm-2 , equal to atmospheric pressure . It is common to express atmospheric pressure in term of height of mercury column. As the atmospheric pressure at a place does not remains constant, hence the height of mercury column also varies with atmospheric pressure .

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Matric Part 1/9th Class Physics Chapter 7 Long Question With Answer for Unit 7 Properties of Matter

9th Class English Medium Subjects

9th Class Urdu Medium Subjects

Online Long Questions For Chapter 7 "9th Class Physics Chapter 7 Long Question Preparation "

Physics (New Book) - 9th Class Physics Chapter 7 Long Question Preparation

Define elasticity. explain deforming force, stress, strain and tensile strain.

What are the features of kinetic molecular model of matter? explain the types of matter

Define atmospheric pressure . explain it

What is the principle of floatation. explain

Explain working of hydraulic press on the basis of Pascal's law.

Explain the application of atmospheric pressure in daily life

State and explain Pascals law

Explain how submarine moves up the water surface down into water

State and explain Hook's law

What is barometer? how atmospheric pressure is measured using a barometer

Prepare Complete Set Wise Questions For Chapter 7 "9th Class Physics Chapter 7 Long Question Preparation "

Set 1

Set 2

9th Class Physics Chapter 7 Long Question Preparation - Set 1

Define elasticity. explain deforming force, stress, strain and tensile strain.

What are the features of kinetic molecular model of matter? explain the types of matter

Define atmospheric pressure . explain it

What is the principle of floatation. explain

Explain working of hydraulic press on the basis of Pascal's law.

Explain the application of atmospheric pressure in daily life

State and explain Pascals law

Explain how submarine moves up the water surface down into water

State and explain Hook's law

What is barometer? how atmospheric pressure is measured using a barometer

9th Class Physics Chapter 7 Long Question Preparation - Set 2

Explain working of hydraulic press on the basis of Pascal's law.

State and explain Archimedes principle. Also prove it

What is the principle of floatation. explain

What are the features of kinetic molecular model of matter? explain the types of matter

Define pressure. explain it with examples

Q no:6 (A) State the Pascal's law. What are its applications in our daily life?

What is barometer? how atmospheric pressure is measured using a barometer

Q no: 7 (A) Explain hydraulic press, on what principle does it work.

Explain the application of atmospheric pressure in daily life

Define pressure and also explain pressure in liquid

9th class Physics Chapter 7 Long Q's (English Medium)