UNIT-1 FOOD

I. Choose the correct answer.

1)The process of utilization of food in body is__________

a)ingestion b)nutrition

c) elimination d)assimilation

2)For photosynthesis ,the green plants need___________

a)oxygen b)nitrogen

c )sunlight d)soil

3)It is an example for omnivorous animal_____________

a)elephant b)man

c)goat d)lion

4) Fungus is a___________________

a)saprophyte b)parasite

c) autotroph c)omnivore

5)Green plant are called________________

a)heterotrophs b)saprophytes c)autotrophs

d)holophytes

II. Fill in the blanks.

1. The arrangement in which autotrophs and hetetrotrophs mutually

gain from each other is called interdependence.

2. Food provides energy

3. Carnivorous animals have sharp pointed canines teeth for tearing

flesh.

4. Plants need sunlight,waterand carbondioxide for photosynthesis.

5. Process of intake of solid food as a whole is called holozoic nutrition.

III. Give two example for each of the following:

1. Autotrophic plants;Roseplant,hibiscus plant.

2. Omnivorous animals ;cat,dog.

3. Herbivorous animals:Goat,cow.

4. Flesh eating animals:Tiger,lion.

IV .Match the following .

1. Autotroph=Green plant

2. Herbivore=Cow

3. Omnivore=Crow

4. Insectivore=Frog

5. Sanguivore=Leech

V. Find the relationship between the first pair of words and complete

the second pair;

1) Parrot : frugivore:: Sparrow: graminivore

2) Saprophytic: fungus:: insectivore:drosera

3) Hibiscus:autotroph:: Eagle: Carrion eater

4) Holophytic: green plants:: holozoic:Amoeba

VI) Give reasons:-

1) Green plants are called autotrophs.

A) Because they prepare their own food.

2) Tiger is a carnivore.

A) Because it eat animals.

3) Round worm is a parasite.

A) Because it lives on other body.

4. The number of plant is more then the number of herbivores.

A) because herbivores can get sufficient food.

VII. under line odd one.

1. mosquito, housefly ,butterfly, amoeba.

2. Carbon di oxide, water, oxygen, chlorophyll.

3. Lion , rabbit, tiger, fox.

4. Liverfluke, earthworm,tapeworm, roundworm.

VIII. Answer the following.

1. Why is food essential for our body?

Ans: Food is essential to do our daily activities such as playing,

walking and to read etc.

2. What is nutrition?

Ans: Eating food , using it for energy ,repair and maintenance of

body structures is called nutrition.

3. Rakshith is confused with steps involved in the process of

nutrition. Help him.

Ans: Ingestion, digestion, absorption, assimilation and egestion are

the five steps of nutrition.

4.Rashmi brought a loaf of fresh bread . She forgot to eat it.After few

days, she remembered and opened the cover, then she observed

some hair like growth on it. What is this growth and type of nutrition

do you recognize?

Ans: Hair like growth is called fungus.it is saprophytic nutrition.

5.Differentiate between saprophytic and parasitic nutrition,with

examples.

Ans: Saprophytic nutrition-If the organisms get their nutrition from

dead or decaying matter then it is called saprophytic nutrition.

Eg-fungus, bacteria

Parasitic nutrition-Getting food by being parasites is called parasitic

nutrition.

Eg-hookworm , roundworm.

6.What are the materials used by a green plants to prepare its food

Name the process.

Ans: Plant prepare their own food using sunlight ,water and carbon

di oxide. This process is called photosynthesis.

7.How do purple bacteria prepare food?

Ans: They use chemical energy to prepare their food.

8.Classify the following organisms into different types of

heterotrophs.

a. woodpecker=insectivores b.hydra-holozoic

c. deer=herbivores d. chemeleon=insectivores

e. valture=carrion eater f. leech= sanguivores

g .monkey=herbivores h. cheetah=carnivores

i. drosera=insectivores j.cat=omnivores.

UNIT-2 WATER

I. Choose the right answer.

1.boiling point of water is 1000C.

2.Pure water is neutral.

3.A homogenous mixture of two or more substances is called

solution.

4.It is a universal solvent water.

5.Positively charged ions are called cations.

6.Ionic solution in the following is salt solution.

7.It is a process which provides water regularly to the earth water

cycle.

8. The quantity of fresh water available on the earth is 3%

II. Fill in the blanks.

1.The scientist who prepared water by burning hydrogen and oxygen

is Henry Cavendish.

2.Water is also called hydrogen monoxide.

3.Water is made of two elements of namely hydrogen and oxygen.

4.In sugar solution water is solvent.

5.In sodium chloride solution sodium chloride is solute.

6.The atoms with extra positive or negative charges are called ions.

7.Removal of soil deposited in pond , river etc is called desilting.

8.Sea water and oceans cover97%of water available on the earth.

9.Direct collection and use of rain water is called rain water

harvesting.

II. Answer the following.

1.Explain the importance of water?

Ans: It plays a vital role in the evolution and survival of life. It is

impossible to imagine life on the earth without water. 2/3 rd of

our body and 9/10 th of our blood is made of water.It also

maintain the body temperature in some organisms.

2.List out the properties of water.

Ans: Properties of water are-

*It is colourless transparent liquid.

*It is odourless and tasteless.

*IT is a compound made of two element namely hydrogen and

oxygen in the ratio 2:1.

*The molecular formula of water is H2O.

3.With the help of an experiment show that pure water is a bad

conductor of electricity.

Ans: Refer page no-21 activity-2.3

4.Draw a neat labeled diagram of the experiment to determine

boiling point of water.

Ans: Refer page no of 22 Fig 2.4

5.What is solution?

Ans: A homogeneous mixture of two or more substances is called a

solution.eg-salt and water,copper sulphate and water.

6.Differeniate between solute and solvent .give one example for

each.

Ans: Substances that dissolves in a solvent is called solute.eg-salt .

The liquid in which a solute gets dissolved is called solvent.eg-water.

7 Name the solvents to be used in each of the following.

Sulphur and oil.

Ans: Sulphur=carbon -di -sulphate

Oil=petrol

8.Take any ten different substances and dissolve the in water .Find

how many substances dissolve?What is your inference.

Ans: *Salt=dissolves

*Sugar=dissolves

*Oil=do not dissolves

*Sand=do not dissolves

*Copper sulphate=dissolves.

Some substances will dissolve and some will not dissolve it is

depending upon their chemical properties,

9.What are ions? Name the the ions formed when the following

substances are dissolved in water.

Ans: Atoms with positive and negative charge are called ions.

a. Potassium chloride=KCl=K+,Cl-

b. Copper sulphate=CuSO4=Cu+,SO4-

c. Sodium chloride=NaCl =Na+,Cl-

d. Sulphuric acid=H2SO$=H2+,SO4

-

10.What is meant by an ionic solution?

Ans: When solute is dissolved in solvent it gets broken down into

positive and negative ions. These ions dissolved in water this is called

an ionic solution.

11. Explain water cycle?

Ans: Due to the heat of the sun the water on the earth evaporates

into the atmosphere forms clouds and again reaches the earth in the

form of rain or snow .It is called water cycle.

12.How is underground water formed?

Ans: Rain water percolates through the soil and gets stored between

the layer of rocks. Such water is called underground water.

13.What do you mean by water scarcity?

Ans: The quantity of water decreasing day by day this situation is

called scarcity of water.

14.Explain the main causes of scarcity of water?

Ans: The main causes of scarcity of water are-

*population=The use of water is continuously increasing due to

pollution.

*Uneven distribution of rainfall=The places with very less rainfall

face water scarcity .

*Decline of underground water table:

Because of continuously using of underground water this problem is

creating.

*pollution of water=De to the pollution the water loses lts quality

and becomes unfit for use.

*Careless use of water

15.What is water pollution?

Ans:The process of polluting water is called water pollution.

Or

By getting polluted water loses its quality and becomes unsuitable

for use .This is called water pollution.

16.How is water pollution caused?

Ans: Domestic, the agricultural and industrial wastes released into

water,make the water polluted.

17What is meant by conservation of water?

Ans: Saving water by using it carefully and in judicious way is called

conservation of water.

18.Explain the methods of conservation of water?

Ans: Water management:*

*Controlling deforestation and overgrazing.

*Interlinking of rivers to transport water from surplus areas to the

area of scarcity.

*Collecting water by constructing checkdams across ponds and

stream helps to check the wastage of rain water.

2.Rain water harvesting:

*Direct collection of rain water and use of rain water is called rain

water harvesting.

19.What is rain water harvesting?

Ans: Direct collection of rain water and use of rain water is called

rain water harvesting.

20.Mention the types of rain water harvesting and its uses.

Ans: a.Collecting water Where it falls:

Collecting water from the roof tops of the houses or building

b. Collecting flowing water:

Collecting rain water for constructing building.

*Checking the running rain water and making it to percolate through

the soil increases underground water level by recharging .It provides

water throughout the year.

IV .Give reason.

1.Ice float on water.

A-Because of its density is less then the water.

2.In cold countries water pipes burst during winter .

A-Due to the anomalous expansion of water.

3.Water is a universal solvent.

A-Because it dissolves large number of substances.

4.Polluted water should be purified before drinking.

A-Because we get diseases if we drink polluted water.

5.The available water on the earth should be conserved.

A-Because it is important for life on earth.

6.It is better to adopt drip irrigation and sprinkler irrigation in

agriculture.

A-By this lesser water can be used for the irrigation of large forming

area.

UNIT-3 SOIL

I.Choose the right answer.

1.Loss of the soil is called soil erosion.

2.The humus content is very low in sandy soil.

3.Tree planting is afforestation.

4.ploughing across the slope is contour farming.

II.Fill in the blanks.

1.soil has humus by which it holds water in it.

2.The top soil contains humus and salts.

3.In northern plains of India alluvial soil is found.

4.The soil is classified depending upon size of soil particles and

colour of the soil

III.Answer the following

1.How is soil formed?

Ans:The particles of rock and humus together form the soil.

2.How does the top soil support plants?

Ans: The top soil provides nutrients to plants. It also provides water

to the plants.

3. What is soil erosion?

Ans. The loss of fertility components of top soil itself due to wind, water

etc this is called soil erosion.

4. Explain the causes of soil erosion?

Ans. The causes of soil erosion are:

1.Storage wind:

Powerful wind carries away fine particles of soil and decomposing

leaves.

2.Fast flowing water:

It loosen the top soil particles and carries away with water .

Deforestation :

Cutting down of trees soil get eroded.

4.overgrazing:

Due to the overgrazing by animals like cattle,goat and sheep the

mentle over the top soil is lost. Then top soil is

Exposed to the wind and rain .Tise leads to soil.

5.What is soil conservation?

Ans :protection of top soil from erosion is called soil conservation.

6. Explain briefly the methods of soil conservation.

The methods of soil conservation are:-

I) Afforestation:- Planting trees is known as afforestation.

II) Construction of bunds:- Construction of bunds along the

boundaries of the field check the soil erosion caused by water

current.

III) Shelter belts:- Planting trees along the edges of the field reduce

soil erosion by wind.

IV) Contour farming:- The circular rows of plants across the slope

check fast running water and their by soil erosion is prevented.

7. What are the components of soil?

Soil consist powder rock, humus, inorganic solutes, soil organisms

and different organisms.

8. Why should the soil be protected?

The soil should be protected because it provide food for living

beings.

9. Explain the types of soil?

I) Sandy soil:- It is dry and gritty to touch. The soil particle have big

space between them.

II) Silty soil:-The colour and turbidity is due to the suspended

sediment of the silt.

III)Clay:-Clay consist of very fine grain material with very narrow air

space between soil particle.

V) Laterite soil:- It contains a balance of all the three soil type- silt,

sand and clay and humus.

VI) Alluvial soil:- Alluvial soil is very fertile and it contain moderate

quantities of humus and nutrients.

10. How does afforestation differ from deforestation?

Ans:Afforestation:-Planting trees is called afforestation.

Deforestation:- Cutting down trees is called deforestation.

UNIT 4

COMBUSTIBLE SUBSTANCE AND FIRE EXTINGUSHIRES

I) Choose the correct answer:-

1. Burning of substance in air is called combustion.

2.An example for a non combustible substance is water.

3. The substance which support fire is oxygen .

4. The most commonly used fire extinguisher is BCand ABC types .

5. Early man used this to extinguish fire water.

6. Phosphorous and sulphur are non metals .

7. It is known as Jalapashana white phosphorous .

8. White phosphorous is always stored in water .

II) Fill in the blanks :-

1. Fire extinguisher is invented by Ambrose godfrey .

2. Francois Carlier invented soda acid fire extinguisher.

3. Carbon dioxide cuts off oxygen supply around a burning

substance.

4. The government organization that fights fire is fire brigade .

5. Phosphorous was discovered by Hennig brand .

6. The main source of phosphorous in nature is calcium phosphate .

7. The emission of green glow by white phosphorous is

phosphorescence .

8. The method of obtaining sulphur from underground is called

frasch .

9. The allotrope of sulphur which has elastic property is plastic

sulphur .

10. The use of sulphur to give hardness to rubber is called

valcanization of rubber .

II) Give reasons:-

1. White phosphorous is always stored in water .

A. Because it catches fire when kept open in air.

2. Plastic sulphur can be stretched to any form.

A. Because it exists as a soft mass.

3. White phosphorous is not used in the manufacture of safety

matches .

A. Because it is highly combustible.

III) Answer the following :-

1. What is combustion? Give two examples for combustion.

A. Burning of any substance in air is called combustion. Example:-

Burning of cracker and burning of paper.

2. List out some combustible substances.

A. Paper, cloth, dry straw, plastic, rubber are some combustible

substance.

3. What factors are required to produce fire.

A. Fire, combustible substance and oxygen.

4. Why is it necessary to control fire?

A. Fire which is very useful to us can destroy life, property and

anything on its way so it is always necessary to control fire.

5. List out the ways to use to extinguish the fire.

A. Removing the burning fuel .

Cutting off oxygen supply.

Cooling the burning material.

6. What is a fire extinguisher/

A. Fire extinguisher is a fire protection device .

7. Name the different types of fire extinguishers.

A. I) Water fire extinguisher .

II) Foam extinguisher.

III)Carbon dioxide fire extinguisher.

IV)Dry chemical fire extinguisher.

V)Halon fire extinguisher.

8. On what principal does a soda - acid fire extinguisher work.

A:- It works on the principal of cutting of oxygen supply and cooling

the burning material.

9. Explain the construction and working of soda- acid fire

extinguisher.

A:- Refer page no. 65 of science textbook.

10.Ranga’s house is on fire ? Abdul advices ranga to use a fire

extinguisher to put off the fire. Do you agree with abdul? Justify

your answer.

A:- No I don’t agree house on fire cannot be put off by fire

extinguisher . He should call the fire brigade.

11.Write any three properties of phosphorous.

A. The properties of phosphorous are :-

I) Phosphorous is a non metal.

II) It is solid in state.

III) It exist allotrophic form.

12.What is allotrophy?

A. The property of an element to exist in different forms is called

allotrophy.

13.Name the allotrophic forms of phosphorous.

A. White phosphorous and red phosphorous are the allotrophes of

phosphorous.

14. List out some difference among the allotropes of phosphorous.

A. White phosphorous is a soft waxy substance. It is highly

combustible . It is insoluble in water.

Red phosphorous exist in powder form. It is not highly combustible.

15.List out some uses of phosphorous.

A. Uses of phosphorous are:-

*Phosphorous is used in the manufacture of fertilizers.

*Phosphorous is used in the preparation of rat poison and some

medicine.

*White phosphorous was used in the manufacture of incidiary

bombs in olden days.

*Red phosphorous is used in safety matches industry.

16.Write any four properties of sulphur.

A:-The properties of sulphur are:-

*It is a non metal existing in powder form.

*It has a bright yellow colour.

*When it burn produce unpleasant odour.

*It is insoluble in water.

17.Which are the allotropes of sulphur? mention their special

features.

A:- Sulphur exists in three allotrophic form. They are rhombic

sulphur,monoclinic sulphur and plastic sulphur.

*Rhombic sulphur:-It is in yellow in coloured crystal. It looks like a

solid with eight faces.so it is called as octahedral sulphur.

*Monoclinic sulphur:-Monoclinic sulphur is a crystalline solid .It

has bright yellow colour. The crystals of monoclinic sulphur are

needle shaped.This allotrophy of sulphur is called prismatic

sulphur.

*Plastic sulphur:-Plastic sulphur exists as a soft mass.It has elastic

property.It ca bent into any shape.It has dark brown in colour.

18.List some uses of sulphur.

A:-Uses of sulphur are:-

*Sulphur is used to prepare sulphuric acid.

*It is used to give hardness to rubber.This is called vulcanization

of rubber.

*It is used in the preparation of skin creams and ointments.

*It is used in the preparation of gun powder,dyes,fertilizer and

pesticides.

UNIT-5 SPEED AND VELOCITY

I .Choose the right answer.

1,the measure of the actual path of movement of an object gives

distance travelled.

2.The measure of the shortest distance between two points gives

displacement.

3.Distance travelled in unit time is termed as speed.

4.Displacement in unit time is termed as velocity.

II. Fill in the blanks.

1.The SI unit of speed and velocity is M/S.

2.The SI unit of displacement is metre.

3.The SI unit of time is second.

4.The formula used to calculate speed is D/t.

5.The formula used to calculate velocity d/t.

III .Answer the following.

1.Define speed.

Ans : Speed is the distance travelled in unit time,

Speed=D/t.

2.Define velocity.

Ans: Velocity is the displacement in unit time.

Velocity=d/t.

3.Differentiate between speed and velocity.

SPEED:

*Speed is the distance travelled unit time.

VELOCITY:

*Velocity is the displacement in unit time.

4.define the terms displacement and distance travelled.

DISPLACEMENT: The measure of the shortest distance between the two

points is called the displacement.

DISTANCE TRAVELLED: The measure of the length of the path between

the two points is called distance travelled.

5.A vehicle travels a distance of 60 km in 2 hours. Calculate its speed.

How long can the vehicle go in the next hour if it goes with the same

speed?

Ans: Speed=D/p=60/2=30km/hrs.

6.There are two pieces of cakes at a reaches another in 10 seconds.

Find its velocity in m/s.

Ans:d=20cm=20/100cm

T=10sec

V=d/t=20/100/10=20/100X10

20/1000=1/50

V=1/50m/sec.

UNIT-6 THE EARTH –A LIVING PLANETS.

I.Fill in the blanks

1,The gravity of the earth bind the atmosphere around the earth.

2.The atmosphere burns the meteors due to friction.

3.The harmful ultraviolet radiations are filtered by ozone layer.

4.The charged particles coming from the space are repelled by

magnetosphere.

II.Answer the following.

1.what dose the atmosphere provide to living beings?

Ans: Atmosphere provide air to living beings .

2.What is the reason for the presence of moderate temperature on the

earth?

Ans:Distance of the earth from the sun not too far nor too near so

moderate temperature exists on the earth.

3.Why is most of the water on the earth in liquid state?

Ans: It is due to the moderate temperature of the earth.

4.Mention the role of ozone layer in protecting the life on the earth.

Ans: Ozone layer protects the earth by filtering the harmful ultraviolet

radiation coming from the sun.

5.List out the factors responsible for life on the earth.

Ans:Air , water ,food materials ,temperature and protection system the

life has evolved nourished and preserved on the earth.

UNIT-7 ATMOSPHERE

I .Choose the right answer.

1.weather phenomenon occurs in this layer tropopause.

2.This layer helps to reflect radio signals to the earth ionosphere.

3.Carbon-di-oxide gas is used in fire extinguisher.

4.Old states and monuments are getting damaged due to acid rain.

5.The amount of nitrogen present in the atmosphere is 78%.

6.Argon is used in the manufacture of semiconductors.

II.Fill in the blanks.

1.The layer of air around the earth is known as atmosphere.

2.The ozone layer is present in the stratosphere layer of atmosphere.

3.The upper boundary of the troposphere is called troposphere.

4.The earth’s surface is getting is warmer due to sunlight.

5.The layer which protects us from the radiations coming from the sun

is ozone.

6.The component of air used by green plants to make their food is

carbon-di-oxide.

7.The second major component of atmosphere is oxygen.

III. Match the following.

1.Nitrogen=manufacture explosive.

2.Oxygen =rocket fuel

3.Carbon –di-oxide=manufacture of dry ice.

4.Argon=incandescent.

IV. Give reasons for the following.

1.Nitrogen is used to control the combustion.

Ans: Because it reduce the reactivity of oxygen in atmosphere.

2.Oxygen is called the supporter of combustion.

Ans: Because it is most reactive of all gases present in a air .It help in

combustion.

3.Jet planes fly in the lower part of the stratosphere.

Ans: Because above the stratosphere is ozone protective layer is

present.

4.The percentage of carbon-di-oxide in air should not increase in the

atmosphere.

Ans: Because it causes global warming.

V.Answer the following.

1.What is atmosphere?

Ans: The air around the earth is called atmosphere.

2.Name the different layers of atmosphere.

Ans: Troposphere ,stratosphere ,mesosphere ,ionosphere and

exosphere are the five layers of the atmosphere.

3.What is troposphere? What is its importance?

Ans: The layer in which we live and weather phenomenon occurs is

called troposphere. It provide life to all living beings.

4.what is the name of the layer or region above stratosphere?

Ans: The name of the layer is ozone layer.

5.Mention the importance of ozone layer.

Ans: Ozone layer which act as a protective layer against harmful

ultraviolet rays.

6.Where is mesosphere situated ? What are its uses ?

Ans: The next to stratosphere is called mesosphere .This is the coldest

layer of the atmosphere .The amount of air in this layer is very less.

7.What is ionosphere?

Ans: The layer next to mesosphere is called ionosphere .

8.Why is ozone layer getting depleted?

Ans: C.F.C is a compound made of chlorine, fluorine and carbon .This

leakage of this compound depletes the ozone layer.

9.Mention the importance of ionosphere and magnetosphere.

Ans: Ionosphere-It is useful in radio broadcasting.

Magnetosphere –It reflect the charged particle from the sun and is the

protective layer of the earth.

10.What are the differences between troposphere and ionosphere.

Ans:TROPOSPHERE-The layer in which we live and weather

phenomenon occurs is called troposphere.

IONOSPHERE- The layer next to mesosphere is called ionosphere.

11.Name the constituents of air ? which is the major compound among

them?

Ans: Nitrogen ,oxygen ,carbon di oxide ,nitric oxide, sulphur -di –

oxide,carbon monoxide are constituent of air.Nitrogen is major

compound among them.

12.Name the active and inactive components of air.

Ans:Nitogen and oxygen are active components .carbon di oxide are

inactive components of air.

13.Write the industrial uses of these gases.

Nitrogen,carbon di oxide,oxygen,argon.

Ans: NITROGEN:

*It is used in the manufacture of explosive.

*It is used in manufacture of steel and other metals.

*In its liquid form it is used as a coolant in industries.

*Liquid nitrogen use in medical field to preserve biological

specimen,blood samples.

CARBON DI OXIDE:

*It is used to prepare dry ice.

*It is used in fire extinguishers.

*It is used in the manufacture of substances such as sugar ,salt, washing

soda and baking soda.

*It is used in the preparation of fertilizer.

OXYGEN:

*It is widely used in steel industry.

*It is used in the production of pig iron.

*Liquid oxygen is used as an oxidant in rockets and missiles.

*It is used to prepare sulphuric acid and nitric acid.

ARGON:

*It is used in the production of wine.

*It is used in the manufacture of high quality steel.

*It is used in advertising boards.

*It is used in incandescent bulbs.

14.What are the effects of interference of man in natural

phenomenon?

Ans: Large quantities of carbon- di- oxide are released into the

atmosphere by the combustion of fossil fuels like petrol, diesel and

coal.A part from carbon -di- oxide, industrial activities produce gases

like nitric oxide ,carbon di oxide and sulphur di oxide .these gases

escape into the earth’s atmosphere and causes environmental

pollution.

15. Explain the following

a. Green house effect b. Acid rain

Ans: Green house effect-Carbon-di-oxide ,sulphur-di-oxide,methane

and C.F.C are the gases responsible for the increase of global

temperature .This effect is called green house effect.

Acid rain-Carbon di oxide , sulphur di oxide and oxides of nitrogen

combine with the water vapour present in the earth’s atmosphere to

from their respective acids. These acid get dissolved in rain water and

pour down as acid rain.

UNIT-8 NATURAL CALAMITIES

I.Fill in the blanks.

1.Electical discharge between clouds or cloud to ground is called

thunderbolt.

2.Negative charges are attracted towards positive charge.

3.The taller buildings and monuments are protected from lightning and

thunder bolt by lighting conductor.

4.Accumulation of excess of water in the river catchment area is called

flood.

5.Deforestation causes soil erosion.

II. Answer the following .

1.Define-

(a)Lightning-When the rain started charging of clouds further increase.

Then the different charges generate a flash of light due to electrical

discharge. This is called lightning.

(b)Thunder-The sudden expansion of air leads to a series of sounds.

This is thunder.

(c)Thunderbolt-Some time the electrical discharge strikes from cloud to

the ground damaging the life and property. This is called thunder bolt.

(d)Flood-Due to many reasons lower regions of land area are covered

by water and cause damages. This accumulation of excess of water in

the catchment area is called flood.

2.Explain the natural and man made causes of flood.

NATURAL CAUSES:

*Global warming-Rising temperature due to global warming leads to

melting of ice in the polar regions which adds to the rise in water level

in the river of that area.

*Coastal flood-Due to the sun’s heat low pressure areas are created.

This leads to storms and cyclones. This also leads to a rise in the level of

sea leading to coastal flood.

MAN MADE CAUSES;

*Deforestation-Soil under the tree hold the water. Due to many

reasons, forests are disappearing .It causes soil erosion which leads to

flood.

*Insufficient number of dams reservoirs and tanks-When heavy rainfall

occurs as water holding capacity of a few number of dams, reservoirs

and tanks surpass a limit water is led out of them in excess. This leads

to flood.

UNIT-9

PHASES OF THE MOON

I. Choose the right answer.

1.The spinning of the moon on its axis is called rotation.

2. The movement of the moon around the earth is called revolution.

3.The increasing phase of the visible illuminated area of the moon is

called waxing.

4.The decreasing phase of the visible illuminated area of the moon is

called waning.

5.The period of rotation of the moon is 27.3 days.

II. Fill in the blanks

1.Moon reflects7% of sun light falling on it.

2.The third day after the new moon is called half moon.

3. The interval between the two successive phases of the moon is 3.75

days.

4.The reason for the appearance of patches on the moon is the

presence of craters on it.

5.The natural satellite of the earth is moon.

II. Answer the following.

1.What is a satellite?

Ans: Satellite is a body that revolves around a planet.

2.Which are the two movement of the moon?

Ans: The moon has two movement namely rotation and revolution.

3.What do you mean by the rotation of the moon?

Ans:The moon spins on its axis. This is called its rotation .

4.What do you mean by the revolution of the moon?

Ans: The movement of the moon around the earth is called its

revolution.

5.What is a lunar month?

Ans: The time interval between one new moon and the next new moon

or one full moon to next full moon is called a lunar month.

6.What is waxing period?

Ans: The increasing phase of the visible illuminated portion of the moon

is called the waxing period.(SHUKLA PAKSHA)

7.What is waning period?

Ans: The decreasing phase of the visible illuminated portion of the

moon is called the waning period.(KRISHNA PAKSHA)

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UNIT-10 ECLIPSES

I. Fill in the blanks.

1 .The event of the earth coming between the sun and the moon in line

is lunar eclipse.

2. The event of the moon coming between the sun and the earth in line

is solar eclipse.

3. A solar eclipse occurs on new moon days.

4. A lunar eclipse occurs on full moon days.

5. During the lunar eclipse if the moon appears in penumbra region

then that is a partial lunar eclipse.

6. If annular and total solar eclipses are observed from different parts

of the earth then that is a Hybrid solar eclipse.

II. Answer the following.

1. What is the an eclipse?

Ans :An eclipse is an event of shadow and light.

Or

Ans: An eclipse is a situation where one celestial object comes in line

with two such objects to make one of the objects to be either fully or

partially invisible from the other tentatively.

2.What is a lunar eclipse?

Ans: The lunar eclipse is a situation where the earth comes between

the sun and the moon in line to make the moon to be either fully or

partially invisible from the earth tentatively.

3.What is a partial lunar eclipse?

Ans: During lunar eclipse if the moon appear in the penumbra region

then that would be the situation of partial lunar eclipse.

4.What is a solar eclipse?

Ans:The solar eclipse is a situation where the moon comes between the

sun and the earth in line to make the sun to be either fully or partially

invisible from the earth tentatively.

5.What are umbra and penumbra region?

Ans : UMBRA REGION-The dark portion of the shadow is called umbra

region.

PENMBRA REGION-Surrounding the umbra region there is the little less

dark region called the penumbra region.

6.Under what conditions does an eclipse occur?

Ans:Where one celestial object comes in line with two such objects so

that they make one of the objects to be either fully or partially invisible

from the other tentatively. under this condition eclipse occur.

7.How many types of solar eclipses are there ?Which are they?Explain.

Ans: There are four types of solar eclipses-total, partial ,annular and

hybrid.

TOTAL SOLAR-Total solar eclipse occurs when umbra shadow of the

moon falls on the earth.

PARTIAL SOLAR ECLIPSE-Partial solar eclipse occurs when only

penumbral shadow of the moon falls on the earth.

ANNULAR SOLAR ECLIPSE-Annular solar eclipse occurs when the moon’s

umbra is too short to reach the earth and hence only the sun’s centre is

covered by the moon leaving the edges uncovered ,producing a ring or

annulus of the sun around the edges.

HYBRID SOLAR ECLIPSE-In hybrid eclipse, annular eclipse is being

witnessed at some parts of the earth at the same total eclipse is

witnessed at some other part of the earth.

8.State the differences between a solar and a lunar eclipse.

Ans: LUNAR ECLIPSE

*The lunar eclipse is a situation where the earth comes between the

sun and the moon in line to make the moon to be either fully or

partially invisible from the earth tentatively.

*Lunar eclipse occurs on a few full moon days.

SOLAR ECLIPSE-

*The solar eclipse is a situation where the moon comes between the

sun and the earth in line to make the sun to be either fully or partially

invisible from the earth tentatively.

*A solar eclipse occurs on a few new moon days.