The Story of Village Palampur - Factors of Production (Part -1)

Factors/Requirements for Production

• Every production is organised by combining land, labour, physical capital and human capital, which are known as Factors of Production.
• There are 4 factors/requirements for the production of goods and services.

1. Land and Raw Materials: - They are a gift of nature and it is essential for any sort of production
2. Labour:-

• Labour refers to the people who work for the production of goods and services.
• There are 3 types of Labour - Skilled / Semi-Skilled  and Unskilled
• Some production activities require highly educated workers to perform the necessary tasks, whereas some other require workers who can do work manually.

3. Capital/Physical Capital : -

• Capital refers to the investments made to produce goods and services.
• There are 2 types of Capital namely Fixed Capital & Working Capital.

• Fixed Capital: The part of physical capital which can be used in process of production over many years and cannot be altered in short periods. Tools, Machinery, Building etc.
• Working Capital: The part of physical capital which can be used in production to make payements and buy other necessary item in short periods.  Raw Materials, Money in Hand

4.  Human Capital : -  

• The person having knowledge & enterprise puts together land, labour and physical capital to produce an output either for himself or to sell in the market. This is the Human Capital.
• Without Human Capital land, labour and capital are useless. Therefore it is the most important factor/requirement for production .

Democracy in the Contemporary World – Glossary

Censorship:

• The suppression of speech or other public communication which may be considered objectionable by the government (controlling body)

Coalition:

• An alliance of people/associations/parties or nations is known as Coalition.

Colony:

• Territory under the direct/immediate control of another state is known as Colony.

Coup

• The sudden overthrow of a government illegally is known as Coup.
• Coup is a French term meaning “a sudden blow or strike to a state”.

Communist State:

•  A state that is governed by a communist party without allowing other parties to compete for power is known as a Communist State.

Martial Law:

• A system of rules that takes effect when a military authority takes the control of the normal administration of justice.

Political Prisoneers

• Persons held in prison/detained/under house arrest, because a government considers their ideas, image or activities as a threat to the authority of state.

Referendum:

• A direct vote in which an entire electorate is asked to either accept or reject a particular proposal.

Strike:

• Mass refusal by the workers/employees to perform work due to certain unjust acts or because of demands not met.

Trade Union:

• An association of workers for the purpose of maintaining/improving the condition of their employment.

Veto:

• The right of a person, party or nation to stop a certain decision or law.
• Veto in Latin means “I Forbid”.
• It has the power to stop a decision, but no power to adopt one.

Democracy in The Contemporary World – Chile (Part 1)

Salvador Allende

• Salvador Allende was the founder leader of Socialist Party of Chile.
• He led the Popular Unity Coalition to victory in the presidential elections of 1970, after which he became  the president of Chile.
• He introduced several policies to help the poor & the workers.
• In 11th September 1973, his government was overthrown by the military & he was killed in the Military Coup.

Policies of Salvador Allende

• After becoming the president of Chile, Allende had taken several policy decisions to help the poor & the workers.

Military Coup of 1973

• The strong opposition against Allende & his policies led to the military coup of 1973.
• On 11th September 1973, the military asked Allende to resign or leave the country, but he refused and knowing the danger he addressed to the people of Chile through radio.
• After which, the military started bombing the presidential palace of Chile (La Moneda) where he died.
• A democratic government of Allende was overthrown by the military through violence & conspiracy in a military coup.
• The government of U.S.A. was unhappy with Allende’s rule and is known to have supported and funded activities that led to the military coup.

General Augusto Pinochet’s Rule

• Augusto Pinochet was a Chilean Army General, he led the military coup of 1973.
• Pinochet then became the president of Chile, and ruled the country for the next 15-17 years.
• Military dictatorship was established in Chile, the military did as they wished and no one could question them.
• Pinochet’s government tortured and killed several of those who supported Allende and those who wanted democracy to be restored.
• Genral Alberto Bachelet, of the Chilean Air Force and many other officers who refuced to join the coup were killed.
• Bachelet’s wife & daughter were put in prison and tortured.

Restoration of Democracy

• Pinochet’s military dictatorship came to an end after he decided to hold a referendum in 1988.
•  The referendum was held to decide whether Augusto Pinochet should continue his rule or not. The voter turnout was 100% and 56% of them opposed him by voting “NO”. 
• Thereafter, Pinochet lost his political and then his military powers.
• Slowly, the role of army in the country’s government  was eliminated.
• Political freedom was restored in Chile, Since then Chile had held over 4 presidential elections in which different political parties have participated.
• General Bachelet’s daughter, Michelle Bachelet, was elected President of Chile in January 2006 after defeating one of Chile’s richest men.

Motion – Distance-Time Graph (Part-5)

Distance-Time graph of a object at Rest

• The distance-time graph of a object at rest is a straight line parallel to the time axis (x-axis).
• The slop of distance-time graph is 0 if the object is at rest.

Distance-Time graph of a object at Uniform Motion

• The distance-time graph of a object moving in uniform motion is a straight line inclined to the time (x-axis).
• Slope: The slope of the graph is the ratio of the vertical change to the horizontal change.
• Slope = Vertical Change/Horizontal Change = Distance Covered/Time take = Speed.
• Slope = Speed (in case of distance time graph).
• The slope of the distance-time graph gives the speed of the object.
• A more steeply inclined distance-time graph indicates greater speed.

Distance-Time graph of a object at Non-Uniform Motion

• Average Speed = Total Distance Covered/Total Time Taken

Motion – Acceleration (Part-4)

• Acceleration is defined as the rate of which the velocity of an object changes.
• Acceleration = Change in Velocity/Time Taken (For uniform velocity only)
• Change in velocity may be due to change in speed or due to change in the direction of motion.
• Acceleration has both magnitude as well as direction, hence it is a vector quantity.
• Acceleration is positive when it is in the direction of velocity.
• Acceleration is negative when it is in the opposite direction of velocity.
• Negative acceleration is also known as Retardation or deceleration.
• If an object is slowing down then its acceleration is in an opposite direction to its motion, i.e. deceleration.
• Acceleration is negative when Initial Velocity > Final Velocity.
• Acceleration is 0 when Initial Velocity = Final Velocity
• Acceleration is positive when Final Velocity > Initial Velocity.

SI Unit of Accceleration

• SI Unit of Velocity ⇒ m/s
• SI Unit of Time ⇒ s
• Therefore, SI Unit of Acceleration ⇒ (m/s)/s = m/s2

Motion – Speed & Velocity (Part -3)

• Speed is defined as the ratio of distance travelled to the time taken to cover that distance.
• Speed is the distance travelled in unit time.
• Speed = Distance Covered/Time Taken
• Average Speed = Total Distance/Total Time (In non-uniform motion)
• SI Unit of Speed ⇒ m/s

• Velocity is defined as the distance travelled in a specific direction in unit time. (displacement in unit time)
• Velocity is the rate of change of displacement in unit time.
• Velocity = Displacement/Time Taken
• SI Unit of Velocity ⇒ m/s

Motion – Distance & Displacement (Part -2)

• Distance is the actual path length travelled by an object in a given time.
• Displacement is the shortest distance between the initial & final position.

•  A physical quantity which has both magnitude and direction is known as a Vector quantity.
• A physical quantity which has only magnitude is known as a Scalar Quantity.
• Examples of Vector Quantity ⇒ Displacement, Velocity, Acceleration
• Examples of Scalar Quantity ⇒ Distance, Speed, Mass, Time
• SI Unite of both Displacement and Distance is Meter.
• The magnitude of the displacement is not always same the distance travelled (it can be less or equivalent).

Motion – Rest & Motion (Part -1)

• If the position of an object does not change with time with respect to some reference point then the object is said to be in Rest.
• If the position of an object changes with time with respect to some reference point then the object is said to be in Motion.
• Reference Point/Orgin (O) is a fixed point with respect to

Rest & Motion are relative

• An object may appear stationary to one person and moving to another (or vice versa).
• All Objects which are stationary on the Earth, are said to be in rest with respect to each other, but with respect to Sun/Moon they all are in motion, in fact we all are in motion.

Matter in our surroundings – Class IX – In-text Solution (Part 4)

(Answers of In-text Question in NCERT Science Text Page 10)

1. Why does a desert cooler cool better on a hot dry day?

Ans: Desert cooler works on the principle of cooling effect of evaporation. In hot and dry days the moisture level is very low in atmosphere & the temperature is high hence it increases the rate of evaporation. Because of faster evaporation, cooler works better.

2. How does the water kept in an earthen pot (matka) become cool during summer?

Ans: 

• In summer moisture level is very low in the atmosphere & the temperature is also high, which therefore increases the rate of evaporation.
• Water from porous wall of earthen pot thus evaporates continuously, which lowers the temperature of water kept in the earthen pot due to the cooling effect of evapouration.
• That is why in summer, water kept in earthen pot becomes cool.

3. Why does our palm feel cold when we put some acetone or petrol or perfume on it?

Ans: When acetone(used in nail-polish remover)/petrol/perfume is poured over palm, it evaporates quickly as these are volatile liquids. The evaporation lowers the temperature of palm and our palm feels cold.

4. Why are we able to sip hot tea or milk faster from a saucer rather than a cup?

Ans: When hot tea or milk is kept in a saucer, the liquid is exposed over a larger surface area as compared to in case of the liquid being kept in a cup. The larger surface area increases the rate of evaporation, thus enables faster cooling. That’s why we are able to sip hot tea or milk faster from a saucer rather than from a cup.

5. What type of clothes should we wear in summer?

Ans: We should wear cotton cloths in summer. As cotton cloths are good absorbent of sweat excreted in summer and also because they enable the sweat to evaporate. Because of evaporation of sweat from the surface of cotton cloth, we feel colder and comfortable.

Matter in our surroundings – Class IX – In-text Solution (Part 3)

(Answers of In-text Question in NCERT Science Text Page 9)

1. Convert the following temperature to Celsius scale.

(Temperature on Celsius scale = Temperature of Kelvin scale – 273)

(a) 300 K

Ans : 300 Kelvin (K) – 273 = Temperature in Celsius = 27⁰C

(b) 573 K

Ans : 573 Kelvin (K) – 273 = Temperature in Celsius = 300⁰C

2. What is the physical state of water at

(a) 250⁰C

Ans: Water boils at 100⁰C and therefore the physical state of water at 250⁰C is gaseous (water vapour).

(b)100⁰C

Ans: Since, the water boils at 100⁰C, thus at 100⁰C water is in transition phase, therefore the water at 100⁰C is in both liquid and gaseous state.

3. For any substance why does the temperature remain constant during the change of state.

Ans:  During the change of state of any substance, the heat supplied or released is utilised in the phase change. Such heat is called latent heat. So, the temperature of any substance remains constant during the change of state.

4. Suggest a method to liquefy atmospheric gas.

Ans: Atmospheric gas can be liquefied by increasing pressure and decreasing temperature.

Matter in our surroundings – Class IX – In-text Solution (Part 2)

(Answers of In-text Question in NCERT Science Text Page 6)

1. The mass per unit volume of a substance is called density. (Density = mass / volume). Arrange the following in order of increasing density - Air, exhaust from chimneys, honey, water, chalk, cotton and iron.

Ans :

• Air is the mixture of gases and it is the least dense among the given matters.
• Chimney exhaust is also a mixture of gases; along with some heavier particles, such as ash. This makes the density of chimney exhaust more than air.
• Cotton is a porous solid and which has lot of air trapped within pores. This makes its volume more than water. Therefore, it is less dense than water.
• Honey is also a liquid; along with some dense particles, hence it is more denser than water.
• Chalk is a solid and as compared to honey is more denser while it is less denser as compared to the Iron.
• Iron is the densest among the given matters.

Air < Exhaust from chimneys < Cotton < Water < Honey < Chalk < Iron

2. (a) – Tabulate the differences in the characteristics of states of matter.

Ans:

2. (b) Comment upon the following: rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy and density

Ans:

• Rigidity: The greatest force of attraction between particles and close packing of particles make solids rigid. Rigidity is one of the unique properties of solids. Because of rigidity a solid has definite shape and volume. Rigidity is negligible in fluid and gas.
• Compressibility: Compressibility is one of the most important characteristics of gas. Because of lot of space between particles, a gas can be compressed to a great extent. Liquid and solid cannot be compressed because of the least space between their particles.
• Fluidity: The ability to flow is called fluidity. The less force of attraction and more space between particles make liquid and gas to flow. That’s why liquid and gas are called fluid.
• Filling of a gas container: Liquids do not fill a gas container completely, while gases fill the gas container completely in which it is kept. This is because the particles of gas can move in all the directions.
• Shape: Solids have fixed shape. Liquid and gas take the shape of the container in which they are kept. This happens because of less force of attraction and more kinetic energy between particles of liquids and negligible force of attraction and highest kinetic energy between particles of gas.
• Kinetic energy: The kinetic energy of particles of solid is the minimum. They only vibrate at their fixed position. The kinetic energy of particles of liquid is more than that of solid. But they can slide above one another. The kinetic energy of particles of gas is the maximum.
• Density: The mass per unit volume of a substance is called density. The density of solid is highest, of liquid is less than solid and of gas is minimum.

3. Give Reasons

(a) A gas fills completely the vessel in which it is kept.

Ans: The force of attraction between particles of gas is negligible, therefore particles of gas move in all directions. Thus, a gas fills the vessel completely in which it is kept.

(b) A gas exerts pressure on the walls of the container.

Ans: As there is only negligible force of attraction between particles of gas, they have the highest kinetic energy. These properties enable the particles of gas to move in all directions and hit the walls of container from all sides. Because of this a gas exerts pressure on the walls of the container in which it is kept.

(c) A wooden table should be called a solid

Ans: A wooden table is should be called a solid because it has definite shape and definite volume, which are the main characteristics of solid.

(d) We can easily move our hand in air but to do the same through a solid block of wood we need a karate expert.

Ans:

•  As Air is gas, its particles are loosely packed and there is negligible force of attraction between its particles. Because of that we can easily move our hand in air.
• But wood is a solid, so the force of attraction between its particles is greatest. The particles of wooden block are closely packed. That’s why we cannot move our hand through a solid block of wood.
• However a karate expert can exert required pressure to break the great force of attraction of the particles of a solid wooden block.

4. Liquids generally have lower density as compared to solids. But you must have observed that ice floats on water. Find out why.

Ans: During freezing of water, some space between the particles of water is left vacant with some air trapped between them. These empty spaces having air in them, makes the density of ice lower than that of water. That’s why ice floats on water.

Matter in our surroundings – Class IX – In-text Solution (Part 1)

(Answers of In-text Question in NCERT Science Text Page 3)

1. Which of the following are matter ? - Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume.

Ans : Chair, Air, Almonds, Cold-drink are matters as they occupy space & have mass.

2. Give reasons for the following observation: The smell of hot sizzling food reaches you several meters away, but to get the smell from cold food you have to go close.

Ans:

• Smell of anything  reaches to us because of diffusion of gases coming from it.
• The rate of diffusion increases with increase in temperature. This happens because of higher kinetic energy due to higher temperature. That is why smell of hot sizzling food reaches to us from several feet away.
• On the other hand, the kinetic energy of gases produced from cold food is low because of lower temperature. Due to this, we need to move closer to a cold food to take its smell.

3. A diver is able to cut through water in a swimming pool. Which property of mater does this observation show?

Ans:

• Water is also a matter.
• Particles of matter have space between them and in case of fluids, the space between the particles is large enough.
• Due to this it becomes easier for a diver to cut through water in a swimming pool.

4. What are the characteristics of the particles of matter?

Ans: Characteristics of the particles of matter:

• The particles of matter have space between them.
• The particles of matter are moving constantly.
• The particles of matter attract one another.

The Fundamental Unit of Life – Short Answer Type Question (SET 2)

1. Write 2 similarities and 1 dissimilarity between mitochondria and plastid.

Ans:

Similarity: Both are double membrane bound and have their own genetic materials.

Dissimilarity: Mitochondria is the site of production of energy whereas plastid is the site of production of food.

2.  Division of labour exists even at intra cellular level. Justify the statement.

Ans:

• Each cell has got certain specific components within it known as cell organelles.
• Because of these cell organelles, a cell is able to perform all its function perfectly and exist(live).
• All cells are found to have the same cell organelles, no matter what their function is or in which organism they are found.
• Each cell organelle performs its unique/special function and constitute to the basic unit of life – cell.  Therefore a division of labour exists even at intra cellular level.

3. List any 2 differences and  2 similarities between a plant cell and an animal cell.

Ans:

Differences: 

• Plant cells have cell wall and plastids, whereas animal cell lack them.
• Plant cells have large sized vacuoles, whereas Animal Cells have small sized vacuoles.

Similarities:

• Both Animal & Plant cell have nucleus.
• Both Animal & Plant cells are bound by membrane.

4. What would happen if an animal cell is kept in distilled water for 24 hours.

Ans: When a animal cell is kept in distilled water for a long time, as there is higher concentration of water in the solution (i.e. Hypotonic), the water will move in to the cell by the process of endosmosis, which will cause swelling of the cell. After the maximum amount of water enters the cell, the cell bursts as it no longer can absorb water.

5. Mention any three features of prokaryotic cell.

Ans:

1. They lack nuclear membrane and well-organised nuclear region/nucleus.
2. They lack membrane bound  cell organelles.
3. Chlorophyll is associated with membranous vesicles.

6. Differentiate between RER and SER. How is endoplasmic reticulum important for membrane biogenesis ?

Ans: RER or Rough Endoplasmic Reticulum looks rough under a microscope as it has ribosomes attached to it, whereas SER has no ribosomes attached to it and appears to be much smoother.

Endoplasmic Reticulum helps in the manufacture of proteins/lipids, which is important for cell functions. Some of these lipids and proteins produced in the ER helps in building of cell membrane, in the process called membrane biogenesis.

7. Describe the role played by the Lysosomes in a cell. Why these are termed as suicidal bags? How do they perform their function?

Ans:

• Lysosomes are a kind of waste disposal system of the cell.
• They help to keep the cell clean by digesting any foreign material as well as worn out cell organelles.
• Foreign materials entering the cell such as bacteria or food ends up in Lysosomes.
• During the disturbances in cellular metabolism lysosomes may burst and the enzymes digest their own cell. Therefoe, lysosomes are also known as suicidal bags.
• Lysosomes are able to do this because they contain powerful enzymes capable of breaking down all organic material.

8.  Distinguish leucoplast from chromoplast based on one feature. Give an example of chromoplast present in plant cell. What is the function of chromoplast in the plant cell?

Ans:

• Leoucoplasts are colourless plastids and stores starch, oil, proteins etc. whereas Chromoplasts are coloured plastids and contain pigments.
• The green pigment in the plant cell is an example of Chloroplast.
• They provide colour to various flowers and fruits in a plant cell.

9.  (a)Why is plasma membrane referred to as selectively permeable membrane ?(b)What are the advantages of its selectively permeability.

Ans:

(a)

• Plasma/Cell Membrane regulates entry and exit of materials across the cell and hence it is referred to as selectively permeable.

(b)

• Cell/Plasma membrane regulates the entry of materials into  the cell, it allows the necessary molecules to enter the cell.
• The intermediate products formed in the cell remain in the cell.
• The secretions and waste substance leave the cell through the cell membrane.

10. (a)Who gave the term Golgi apparatus? (b)Name one cell organelle that is formed by Golgi Apparatus (c) Write any 2 functions of Golgi Apparatus

Ans:

(a)Camillo Golgi

(b) Lysosomes

(c) Functions of Golgi Apparatus include:-

• Packaging and dispatching of materials synthesised by ER.
• Converts Simple Sugars into complex sugar.
• It is involved in the formation of Lysosomes.

11. (a) Why is Endocytosis not found in plants? (b) State and explain the process by which amoeba obtains its food.

Ans:

(a) For endocytosis to occur the cell membrane must be flexible, but in plant cell, the outer covering of the cell membrane i.e. cell wall is very rigid. Therefore endocytosis does not occur in plants.

(b) The process by which amoeba engulfs food is known as Endocytosis. The flexibility of the cell membrane enables amoeba to engulf its food and other materials from its external environment.