NOTES / SOLVED EXERCISES GENERAL SCIENCE 4 (IV) PTB LHR (2014-15)

 

NOTES: NEW OXFORD PRIMARY SCIENCE LEVEL 4 SECOND EDITION NICHOLAS HOSBURGH

U: 1                                   HUMAN BODY EX: (P 8-9)

A 1. B 2. D 3. A 4. E 5. C

B 1. tissue 2. The heart3. vertebrate 4. a joint 5. a ligament 6. a hinged 7. a ball and socket 8. smooth/  involuntary        9. a tendon 10. musculoskeletal system

 

C Answer the following Questions:

 

Q No.1

What are the main functions of the skeleton?

ANS:

The main functions of the skeleton are as follows:

• It gives strength and support to the body.

• It frames the shape of the body.

• It protects some important and soft internal organs, such as the lungs, heart and brain.

• It helps us to move.

Q No.2

a) Define joint. Which two types of joints have been discussed in this  HUMAN BODY?

b) Where are each of them found in your body?

Write anyone activity you can perform with the help of these joints?

ANS:

a) A joint is the place in a vertebrate’s body where two or more than two bones meet with the help of a tissue called a ligament.

i) Ball and socket joint, found in the hip bone, and the shoulder bone.

ii) Hinged joint, found in the elbows, knees and the joints of our fingers and toes.

b)     Hinged joint: When we bend our elbows to hold something, or when we walk or bend our legs, we use the hinged joints of the knee or ankle.

Ball and socket joint: When we spin something into the air, we use the ball and socket joint of our shoulder.

Q No.3

Differentiate between voluntary and involuntary muscles along with an example of each one.

ANS:

The two types of muscles are:

        VOLUNTARY MUSCLES:

They can be controlled.

Example, the skeletal muscles.

         INVOLUNTARY MUSCLES :

They are smooth muscles . They cannot be directly controlled,

Example: the stomach, intestines, and bladder.

Q No.4

How many types of muscles are there? Describe each of them with an example.

ANS:

Types of muscles                                              Examples

smooth                                                                      stomach, intestine, bladder                                           cardiac                                                                         heart

skeletal joint,                                                         ligament, tendon

or

TYPES OF MUSCLES EXAMPLES
smooth stomach
cardiac heart
skeletal tendon
Q No.5

Suggest any two ways to take good care of muscles and bones.

ANS:

Doing plenty of exercise and eating calcium-rich food helps to build strong muscles and bones.

Or

TWO WAYS TO TAKE GOOD CARE OF MUSCLES AND BONES:

1-    plenty of exercise

2-    eating calcium-rich food

 

U :2                                 TEETH  EX: (P: 12)

A 1. C 2. E 3. D 4. F 5. A  6. B

 B: Answer the following Questions:

 

Q No.1

                    What are a child’s first set of teeth called?

ANS:

A child’s first set of teeth are called baby teeth or milk teeth.

Q No.2

                  How and why do teeth decay?

ANS:

Teeth decay if they are not brushed regularly.

Q No.3

                      Which teeth are used for grinding food?

ANS:

Molars, or the back teeth, are used for grinding food.

Q No.4

                How do you take care of your teeth?

ANS:

I brush my teeth daily

C: Label the different types of permanent teeth in the picture.

 

 

U:3    FOOD AND BALANCED DIET        P:17-19

A 1. D 2. C 3. A 4. B

B 1. wheat 2. bread  3. carbohydrate 4. fats and sweets 5. Eggs

 

C: Answer the following Questions:

 

Q No.1

Why do we need food?

ANS:

We need food

1-to grow,

2- gain energy, &

3- remain healthy.

Q No.2

What do we mean by a balanced diet?

ANS:

A balanced diet means eating the right variety of food in the right amounts.

Q No.3

What do proteins do for your body? Name four foods which have a lot of protein in them.

ANS:

Proteins are body building foods. They help our body to build up and repair tissues and muscles.   Some sources of protein are fish, beef, mutton, beans, chicken and eggs.

Q No.4

How does fibre help your body?

ANS:

Fibre helps to absorb extra water. It helps the digestive process.

Q No.5

Why does the body need carbohydrates?

ANS:

Carbohydrates are a quick source of energy for the body.

Q No.6

Do you need energy while you are sleeping? Explain your Ans, giving reasons.

ANS:

We need energy even when sleeping. While we are sleeping, our heart, brain, lungs and stomach are performing their jobs. They need energy to carry on their work.

Q No.7

What are   the five food groups? Explain how each food group helps your body.

ANS:
Q No.8

Write the foods in their correct column according to the groups they belong to:

spaghetti, spinach, fish, carrot, milkshake, lassi, sweets, rice, cheese, cooking oil, eggs, chicken, chapatti, tomato, yogurt, cake

ANS:
Grain Fruits & vegetables Milk Meat Fats & sweets
Spaghetti rice chapatti Spinach, carrot, tomato milk shake ,lassi, cheese, yogurt Fish, chicken, eggs cooking oil, cake, sweets
Q No.9

What is a food PYRAMID? What does it tell you?

ANS:

The food pyramid is a guide. It shows that not all foods are equally healthy. It guides us about how much we should eat from each of the food groups.

Q No.10

Which food group should form the largest portion of our diet?

ANS:

The grain group should form the largest portion of our diet.

Q No.11

Drinking plenty of water and exercising is important. Explain why?

ANS:

          Drinking plenty of water is important, because water carries all the materials to the cells of our body.

             Exercise makes us feel good. It improves our blood circulation and keeps the bones and muscles healthy and strong.

 

U:4              ANIMAL KINGDOM              P: 24-25

Answer the following Questions:

 

Q No.1

What is meant by classification? Why do scientists classify things?

ANS:

Classification means to put things into groups or classes, according to their characteristics.

Scientists use classification to make the identification and study of things easier.

Q No.2

Define the following terms with examples of each:

a) Cold-blooded animal

b) Warm-blooded animal

ANS:

a) COLD-BLOODED animals take on the temperature of their surroundings. They are warm, when their environment is warm, and cold if their environment is cold. Fish, frogs and snakes are examples of cold-blooded animals.

b) WARM-BLOODED animals maintain a constant body temperature. This means that they do not depend upon the temperature of their environment to keep them warm.

Q No.3

What is the main difference between vertebrates and invertebrates?

ANS:

Vertebrate animals have a backbone.

Invertebrate animals do not have a backbone.

Q No.4

Think of two different kinds of vertebrates. List at least two similarities and two differences between them.

ANS:

 

Q No.5

Write the three ways in which birds are different from other vertebrates.

ANS:

i)                          -Birds have feathers on their body and most are able to fly.

ii)                        -They lay hard-shelled eggs.

iii)                      -They have a beak.

Q No.6

HOW WOULD A SCIENTIST  DESCRIBE THE FOLLOWING

A-    FISH

B-    A MAMMAL

C-    AN AMPHIBIAN

ANS:

a)       A fish:

• It is a vertebrate.

• It is a cold-blooded animal.

• Its body is covered with scales.

• It lives and lays its eggs in water.

• It breathes through gills.

 

b)       A mammal:

• It is a warm-blooded vertebrate.

• Its body is covered with hair.

• Most mammals give birth to babies.

• The young feed on milk produced by the mother.

• Mammals breathe through their lungs.

 

c)       An amphibian:

• It is a cold-blooded vertebrate.

• It has moist, slippery skin.

• It can live both on land and in water.

• It lays eggs in the water.

• It breathes through its skin and lungs.

Q No.7

A crocodile can also spend some time in water. List at least three WAYS in which it is different from a frog.

ANS:

a) A crocodile has dry scales on its body, while a frog’s skin is moist and slippery.

b) It lays eggs on land while the frog lays eggs in water.

c) A frog breathes through its skin when it is in water and through its lungs when it is on land.

Q No.8

How can you prove that the bat is a mammal?

ANS:

A bat is a mammal because it possesses all the characteristics of mammals. It is warm-blooded. It has hair on its body. It gives birth to live babies. It feeds its babies with its own milk.

 

B 1. b) salamander2. d) They all lay eggs.3. a) frog4. c) skin5. d) salamander 6. b) lungs 7. d) They are warm-blooded.8. c) feathers 9. b) platypus 10. d) mosquito

C 1. cold-blooded  2. warm-blooded 3. invertebrates 4. vertebrates

 

U:5            ANIMAL REPRODUCTION          P:28

Answer the following Questions:

Q No. 1

What is the yellow part inside an egg called? What is the function of this part of the egg?

ANS:

The yellow part inside the egg is called the yolk. This is the food store for the embryo.

Q No.2

What is the clear sticky liquid inside the egg called? What is the function of this part of the egg?

ANS:

The clear, sticky liquid inside the egg is called the albumen or egg white.    The albumen cushions the growing embryo against shocks, protects it from drying out and provides additional nutrients for its growth.

Q No.3

What is the egg shell of insects made up of?

ANS:

The egg shell of insects is made up of chitin.

Q No.4

Which group of animals does not lay eggs?

No mammals, except the duck-billed platypus and echidnas, lay eggs. They give birth to live babies.
Q No.5

Why do fish lay many eggs?

ANS: Fish do not take care of their eggs. Since their eggs can be damaged or eaten by other animals in the water, they lay many eggs.
Q No.6Why are the eggs laid by fish and amphibians protected by a jelly-like substance?
ANS:

The eggs of fish and frogs are very soft. They do not have a shell around them and they may dry out in the air, so they are protected by a jelly-like substance.

Q No.7

Where does the embryo that is growing inside the egg, get its food from?

ANS: The embryo which is growing inside the egg gets its food from the albumen and yolk.

 

B Fill in the blanks.

1 )’The new creature/animal growing inside the egg is known as the ———————                                                                                                                       2) The outside covering of a bird’s egg which protects the embryo is called————–                                                                                                    3) The yellow part of the egg which stores food for the embryo is called —————–                                                                                 4) The clear sticky liquid inside an egg is called—————————————-

5 )The outer covering of an insect’s egg is made up of a substance called—————–

6)——————————–,—————————————–,————————————- and——————————————- all lay eggs of different sizes.

ANS:                                                                                                                                       1. Embryo           2. egg shell                    3. Yolk                 4. albumen or egg white                 5. Chitin              6. fish, birds, reptiles and amphibians

  1. Draw a neat diagram of a bird’s egg and label the following parts in your diagram:

egg shell                                     2 albumen                         3 yolk

 

 

U:6                            PLANTS           P:34-37

A 1. E photosynthesis 2. C. non-vascular plant              3. F. unicellular  4. G. multicellular 5. D. Fronds           6. B. angiosperms 7 A. Chlorophyll

 

B 1. c. moss  2. b. fungi  3. c. spore 4. d. spores            5. b. produce spores 6. a. vascular  7. a. moss                 8. a. photosynthesis  9. d. chlorophyl 10. b. Wool

 

C 1. chlorophyll 2. photosynthesis  3. algae                  4. botany 5. fronds 6. spores  7. rhizoids                        8. flowering plants  9. conifers  10. gymnosperm

 

D: Answer the following Questions:

Q No.1

Define the following terms.

a) Photosunthesis                                             b) Fronds

c) Cellulose                                                            d) Vascular sustem

Ans:

a)    Photosynthesis:

The food making process of plants is known as photosynthesis. Plants make their food with the help carbon dioxide, water, chlorophyll and sunlight.

 

b)   Fronds :

The leaves of ferns are known as fronds.

 

c)    Cellulose:

The wall of a plant cell is made of cellulose.

 

d)   Vascular plants :

                       Plants which have a well-developed system to transport water and food through the plant are known as vascular plants. They have proper roots, stems and leaves.

Q No.2

List any two ways in which plants are different from animals.

Ans:

Two ways in which plants are different from animals are:

a)    -Plants can produce their own food because they possess chlorophyll.

Animals do not have chlorophyll so they cannot produce their food.

b) –The cells of plants have cell walls made of cellulose.

Animal cells do not have cell walls.

Q No.3

Write at least five ways in which plants are useful for other living things.

Ans:

a) Plants provide shelter and food to many other animals.

b) Plants release oxygen during photosynthesis which animals need for breathing.

c) Chemicals taken from plants are used to make medicines.

d) Plants provide materials such as wood to make houses, furniture and paper.

 

 

Method ofreproduction How does

water and food

travel in this

plant?

Which body

ports ore

present?

 

Class of plants

 

Ans:
CLASS Which body ports are

present?

 How does water and food travel in this plant? Method of reproduction
Algae simple body, no distinguishable parts live in water to absorb water directly by spores or fragmentation
Moss does not have true roots, stem and leaf but has root like structures known as rhizoids Water is absorbed by the whole body of the plant. by spores
Ferns have true roots, stem and leaves through their roots and stem or through their vascular system by spores
Conifers have all parts except fruits and flowers through their roots and stem or through their vascular system by seeds
Flowering

plants

have all parts including flowers and fruits through their roots and stem or through their vascular system by flowers

 

Q No.5

            Explain how mosses are similar to ferns and how these two groups are different from each other.

Ans:

Similarities Like mosses, ferns also lack fruits and flowers. Fern also reproduces by spores.

        Difference: Unlike mosses ferns have a vascular system. They possess true roots, stem and leaves.

Q No.6

Can algae and mosses grow in the desert? Support your Answer with reasons.

Ans:

No, algae and mosses cannot grow in the desert because they both lack roots, stem and leaves, so they need to grow near water. However, the desert is a waterless environment.

Q No.7

               Mosses do not have true roots and stems. How do they keep themselves fixed in the soil?

Ans:

Mosses have root-like structures called rhizoids which fix them in the soil.

Q No.8

Compare and contrast conifers and flowering plants.

Ans:

Both of them are vascular, seed-bearing plants. Conifers do not produce flowers and fruits. The seeds of conifers are not enclosed in a fruit or flower, whereas the seeds of flowering plants are enclosed in their flowers or fruits.

Q No.9

      What special features or structures must a plant have to

a) grow taller?

b) live in the desert?

Ans:

a) To grow taller, a plant must have a well-developed vascular system.

b) To live in the desert a plant must have long roots which can search for water for the plant, and thick leaves to prevent water loss through transpiration.

Q No.10

Compare fungi with plants and animals.

Ans:

Fungi are a special case. They cannot be classified as a plant because they cannot produce their own food; secondly, their cell walls are not made of cellulose. They cannot be classified as animal because their cells have cell walls.

 

U:7      POLLUTION AND FERTILIZATION      P: 44-45

A 1. E  2. F 3. A  4. C 5. B  6. D

 

B 1. pollination 2. sepals 3. stigma 4. pollen tube          5. calyx  6. insects 7. anther  8. wind  9. nectar 10. Fertilization

 

C: Answer the following Questions:

Q No.1

Define the following terms.

a)      Cross-pollination

b)Self pollination

ANS:

a) Cross-pollination    If the pollen grains of a flower fall onto the stigma of another flower, it is called cross-pollination.

b) Self-pollination   If the pollen of a flower falls onto the stigma of the same flower, it is called self-pollination.

Q No.2

a) What is fertilization?

b)      How does a flower-get fertilized? Explain in steps starting from the
landing of pollen onto the stigma to the formation of seeds and fruits.

ANS:

a)    When the male cells combine with the female cells to produce a

new organism, it is called fertilization.

b) The process of fertilization:

1.  Pollen grains get stuck to a
bee when it visits a flower.

2.  The bee travels to another
plant of the same type.

3.   The pollen grains fall on the
stigma and pollination takes place.

Q No.3

Brightly coloured petals attract insect pollinators. How are the flowers, which do not have brightly coloured petals, like grasses, pollinated?

ANS: Grasses, cereals and some trees, which do not have brightly-coloured petals, are pollinated by the wind.
Q No.4

What is a flower and what is its function?

ANS: The flower is the reproductive organ of a plant. Flowers help in the reproduction of plants.
Q No.5

Construct a table, like below, in your note book and describe the functions of all parts of the flower you have studied in this chapter.

Parts of the flower Function Drawing
     
     
     
Q No.6

            Draw a neat diagram of a flower and label the following parts in it. sepals, petals, stigma, style, ovary, ovules, anther, filament

ANS:
Q No.7

              Draw neat and well-labelled diagrams to show the following processes:

a) Self-pollination

b) Cross-pollination         

ANS:
Q No.8

           activity

ANS:

 

U:8    MIXTURE AND SOLUTION                    P:50-51

A 1. B 2. D 3. C 4. A

B 1. clear 2. solvent  3. oxygen 4. soluble 5 insoluble

C 1. b 2. a 3. a 4. c 5. A

 

D: Answer the following Questions:

Q No.1

Define the following terms, giving example of each:

a)      Solute

b)      Solvent

c)      Soluble

d)      Insoluble

ANS:

a) A solute is a substance which can be dissolved in a solvent to form a solution. Examples;.

b) A solvent is a substance in which a solute can be dissolved to form a solution. Examples;.

c) If a substance can completely dissolve in water, it is said to be soluble. Examples;.

d) If a substance does not dissolve in water, it is said to be insoluble. Examples;.

Q No.2 Explain what type of mixture a solution is?
ANS:

A solution is a clear, transparent, homogenous, mixture.

Q No.3

Name at least three common solutions you use in your daily life.

ANS:

1.                              2.                                          3.

Q No.4

Is a solute always in solid form? Support your Ans with examples from your daily life.

ANS: No, solutes can also be in gas or liquid form. An example of a liquid solute is lemonade.  Lemon juice, which is liquid, is mixed with water to make lemonade.

An example of a gas solute is the presence of oxygen in water that enables sea animals to breathe and survive in water.

Q No.5

Do you know why carbon dioxide is added in fizzy drinks?

ANS: Adding carbon dioxide to fizzy drinks makes them taste better and creates bubbles and fizz in the drink.

 

U:9           SEPARATING MIXTURES             P: 57-58

A: Column A contains DEFINITIONS of the terms and Column B contains these terms.        Match Column A with Column B and write the appropriate letter in the blanks given below.

Column A Column B
1-the solid remains on the filter paper after filtration A-decantation
2-the liquid passes through a filter paper B-evaporation
3- the method used to separate heavier solid particles from a liquid C-residue
4- the method of separation which needs water to be boiled D-Filtrate
ANS: 1. C     2. D     3. A      4. B

 

B:  FILL IN THE BLANKS.

1 The solid which remains on the filter paper after filtration, is called——————————and the liquid which passes through the filter paper is called—————————————

2 The process which changes liquid into gas is known as———————————————-

3 The process which is used to separate heavier solid particles from a liquid is called———————————-

4 Evaporation is a method of separation used to separate———————————— solid from a liquid.

5 Chalk powder can be separated from liquid using a method known as———————————

ANS:

1. residue, filtrate

2. evaporation

3. sedimentation

4. soluble

5. filtration

C: CIRCLE THE CORRECT ANS:

1-Which of the following methods will be used to separate chalk powder from water?

  1. a) evaporation b) decantation c) filtration

2- The separation method that involves heating to change liquid into a gas is known as:

  1. a) filtration b) evaporation c) sedimentation

3- Which of the following would you use to separate pieces of iron from pieces of plastic?

  1. a) cloth b) filter paper c) magnets

4- Which method of separation is used when draining water from rice?

  1. a) evaporation b) filtration c) decantation

5- Electromagnets are used to sort __________________________________________________ from junk.

  1. a) plastic b) metals                                                                                           c) wood
ANS: 1. C    2. B    3. C    4. B    5. B

 

D: Answer the following Questions:

Q No. 1

What type of mixture can be separated using the filtration method?

ANS: The mixture of insoluble solid and liquid can be separated using the filtration method.
Q No. 2

Give an example of a mixture you can separate using evaporation?

ANS:

SEA WATER

We can separate it by evaporation.

Q No.3 You have a mixture of sand, salt and iron filings. How will you separate all the components of this mixture?
ANS:

We shall separate  components by suing:

a.      Decantation

b.     Evaporation

c.      Magnetic method

Q No.4 Suppose you are making some tea. You do not have a strainer or a clean piece of cloth. Which method would you use to separate the tea leaves from the tea?
ANS:

We shall use DECANTATION method to separate the tea leaves from tea.

Q No. 5

Where do we use the magnetic method of separation? Give an example from your daily life.

ANS:

Magnets are used to separate magnetic and non-magnetic materials.

For example;

Electromagnets are used to sort metal out from scrap.

Q No.6

How will you separate the components of a mixture consisting of salt, sand and water?

ANS:

EVAPORATION and DECANTATION:

These methods will be used to separate the components of a mixture which consists of;

-Salt

-Sand

-Water

 

U:10           THE EARTH IN SPACE                P:62-63

A: Match each DEFINITION in COLUMN A with the TERMS in COLUMN-B and write the correct Ans in the spaces given below.

 

COLUMN A COLUMN-B
1-the spinning of a body on its axis A-year
2-the orbiting of one object  around another B-orbit
3- to lean, incline, slope, or slant C-revolution
4-the path in space of one object as it goes around another body. D- rotation
5- the time the Earth takes to complete one rotation on its axis. E-tilt
ANS: 1. D     2. C     3. E     4. B     5. A

 

B FILL IN THE BLANKS.

1 The imaginary line on which the Earth rotates is called the—————————–

2 The movement of the Earth, causing day and night, is called——————————

3 The Earth moves around the Sun and this movement is called—————————–

4 The Earth takes ———————day to spin once on its axis.

5 The Earth takes ——————————–days to complete one orbit around the Sun.

6 The path in space of one body as it goes around another body is called ——————

7 Changing seasons on the Earth are caused by the Earth’s tilt on its——————

8 The area of the Earth which leans towards the Sun has the—————— season

9 The area of the Earth which leans away from the Sun has the ————————-season.

I0 The time the Earth takes to rotate once on its axis is called——————————

ANS:

1. axis 2. rotation 3. revolution 4. one 5. 365   6. orbit   7. axis

8. summer   9. winter   10. day

C: ENCIRCLE THE CORRECT ANS.

1 How many days does the Earth take to complete one orbit around the Sun?

  1. a) 265 b) 365                                 c) 465

2 How many hours does the Earth take to complete one turn on its axis?

  1. a) 24 hours b) 34 hours                      c) 44 hours

3 Which of the following is correct? Seasons are caused due to the

  • distance of the Earth from the Sun.
  • rotation of the Earth on its axis.
  • revolution and tilted axis of the Earth.

4 The fixed path of the Earth on which it moves around the Sun is called its

  1. a) axis b) orbit                              c) Equator

5 The time the Earth takes to rotate once on its axis is called a—————————-

  1. a) day b) month c) year

6 The time the Earth takes to revolve once around the Sun is called a——————-

  1. a) day b) month         c) year
ANS: 1. b    2. a    3. c    4. b    5. a    6. c

D:ANSWER THE FOLLOWING QUESRIONS.

Q No.1

Why is summer hotter than winter?

ANS:

Summer is hotter than winter. Because Earth is tilted towards the Sun in summer. It receives greater heat and light.

Q No.2

How many seasons are there? Name them?

ANS:

There are four seasons;

1-    spring

2-    summer

3-    autumn

4-    winter

 

U:11                     HEAT                        P:68-69

A: Match each DEFINITION in COLUMN A with the TERMS in COLUMN-B and write the correct Answers in the spaces given below.

 

COLUMN A COLUMN-B
1- the total kinetic energy of particles of a substance A- heat
2- the average kinetic energy of particles of a substance B- thermal energy
3- the flow of energy from a warmer to a cooler object C- temperature
ANS: 1. B     2. C    3. A

 

B: FILL IN THE BLANKS.

1 The average kinetic energy of particles in a substance is called——————–

2 The total energy of particles in a substance is called——————————–

3 The flow of thermal energy from a warmer object to a cooler object is known as—————————————-

4 The instrument which is used to measure temperature is called——————

5 All matter is made of tiny particles called ———————

6 The normal human body temperature on the Celsius scale is———————-

7 The melting point of ice is———————- Fahrenheit and——————————Celsius.

8 The temperature at which pure water boils is ———————————–Fahrenheit and————————–Celsius.

9 Temperature that is lower than 0°C is written with a—————————————————————sign.

10 Nothing can get colder than—————————————Celsius and this is called———————————–

ANS: 1. Temperature  2. thermal energy 3. Heat 4. thermometer

5. atom 6. 37oC   7. 32oF ,   0oC  8. 212oF and 100oC 9. minus –           10. –273oC ,   absolute zero

 

C: CIRCLE THE CORRECT ANSWER.

1 Temperature is the————————kinetic energy of particles.

  1. a) total b) average                         c) partial

2 Thermal energy is the—————               energy of particles.

  1. a) total b) average                         c) partial

3.The flow of thermal energy from warmer object to a cooler object is known as————————————-

  1. a) heat b) temperature c) potential energy
  2. Any temperature on the Celsius scale which is lower than that of melting ice

(0°) is written with a ————————-sign.

  1. a) minus b) plus                                c) multiply

5.The normal human body temperature on the Celsius scale is———————

  1. a) 37° b) 40°                                   c) 6°
ANS: 1. b    2. a    3. a     4. a      5. a

D: ANS THE FOLLOWING QUESRIONS.

 

Q No.1

Define the following terms:

a)      Heat

b)      Temperature

ANS:

a.     HEAT Heat is the flow of thermal energy from a warmer object to a cooler object.

b.    TEMPERATURE Temperature is measure of the average kinetic energy of atoms.

Q No.2

Which two scales are commonly used to measure temperature?

ANS:

FOHRENHIET and CELSIUS scales are commonly used to measure temperature.

Q No.3

Which instrument is used to measure temperature?

ANS:

THERMOMETER is used to measure temperature.

Q No.4

What happens to the liquid of the thermometer when the air around it gets?

a.            Warmer

b.     Cooler

ANS:

a.     When the air  around the thermometer gets warmer;

The liquid inside the air begins to expand. It moves upwards.

b.     When the air  around the thermometer gets cooler;

The liquid inside the air begins to contract. It moves downwards.

 

U:12        CIRCUITS AND SWITCHES            P:75-76

A: Match each DEFINITION in COLUMN A with the TERMS in COLUMN-B and write the correct Ans in the spaces given below.

 

COLUMN A COLUMN-B
1- the complete path along which electricity flows A- conductor
2- a device or connection used to turn on or off an electrical appliance B- insulator
3- a material which allows electricity to pass through it C- circuit
4- a material which does not allow electricity to pass through it D- switch
ANS: 1. C     2. D     3. A     4. B

 

B Fill in the blanks.

1 Electricity which flows through a material is called—————————-

2 A complete path for electricity to flow is called———————————-

3 If there is a gap or break in the circuit, it is called an—————————————-circuit.

4 If there is no gap or break in the circuit, it is called a———————————————-circuit.

5 The device which is used to turn on or off an electrical appliance is called a————————————————–

6 In a —————————————–circuit, the appliances are connected in a line, one after the other.

7 In a —————————-circuit, the current flows through different branches or paths.

8 A substance which allows electricity to pass through is called an—————-

9 A substance which does not allow electricity to pass through is called———-

ANS: 1. current

2. circuit

3. an open or incomplete circuit

4. closed or complete circuit

5. switch

6. series

7. parallel

8. conductor

9. insulator

 

C: CHOOSE THE CORRECT ANS.

1 The materials which allow electricity to pass through them are called

  1. a) insulators b) conductors c) none of above

2.The materials which do not allow electricity to pass through them are called

  1. a) insulators b) conductors c) none of above

3 Which of the following is an example of an insulator?

  1. a) rubber b) copper                           c) silver

4 Which of the following is an example of a conductor?

  1. a) rubber b) copper                           c) wood

5 Which of the following is an example of a mains-powered appliance?

  1. a) torch b) wrist watch                 c) refrigerator

6 Which of the following is an example of a battery-powered appliance?

a)washing machine b)remote control c)air conditioner

ANS: 1. b    2. a    3. a    4. b    5. c    6. b

 

D: ANS THE FOLLOWING QUESRIONS.

Q No.1

Define the following terms.

1 conductor

2       insulator

3       Electric current

4 Circuit

ANS: 1conductor: If a material allows electricity to pass through it, it is called a conductor.

2 Insulator: The material which does not allow electricity to pass through it is called an insulator.

 3 ELECTRIC CURRENT

Electricity which flows through a material is called  electric current.

4 CIRCUIT:

The complete path along which electricity flows is called Circuit.

Q No.2

What is a switch used for?

ANS:

A switch is used to turn on or off an electrical appliance.

Q No.3

Compare series and parallel-circuits?

ANS:

SERIES CIRCUITS:

The appliances (bulbs, lights) are connected one after another.

PARALLEL CIRCUITS:

The current divides into two or more paths before going back to battery. 

Q No.4

Draw and label the following circuits with a battery, wire and two lights?

ANS:

 

 

U:13 FORCES AND MACHINES

P:: (P: 82-84)

A: Match each DEFINITION in COLUMN A with the TERMS in COLUMN-B and write the correct Ans in the spaces given below.

COLUMN A COLUMN-B
two inclined planes joined back

to back, used to cut or split things apart

A-inclined plane

 

2- a rigid bar or rod that rests and moves on a support, and is used to move a heavy load easily B- pulley

 

3- a rope or string wound around a grooved wheel, used to move objects up, down or across C- screw

 

4- a slanting surface used for moving objects from lower to higher, or higher to lower surfaces easily D- wedge

 

5- an inclined plane wrapped around a cylindrical pole that is used to fasten, or hold things together E- lever
ANS:   1. D    2. E    3. B    4. A    5. C

 

B Fill in the blanks.

1-A device or tool used to make the work easier and faster is called a ——————-

2- A ————————–machine has few or no moving parts.

3- A ————————————machine is made up of two or more simple machines combined together.

4- A simple machine made up of a bar or rod, which rests and turns on a fixed point is called a———————————————————–

5- A simple machine used to cut or split things apart is called—————————–

6- A simple machine that is used to fasten or hold materials together is called——————————

7- A fork is an example of a simple machine called a———————————-

8- A simple machine with a slanting surface, used to move heavy loads up or down is called a——————————–

9- A simple machine consisting of a rope or string, wound around a grooved wheel is called————————————-

10- The rod that goes through the wheel and helps the wheel to move is called ————————————————————-

ANS:

1.machine 2. simple 3. compound 4. lever 5. wedge

6. screw 7. wedge 8. inclined plane 9. pulley 10. axle

C CIRCLE THE CORRECT ANSWER.

1-Which of the following is not an example of a simple machine?

  1. a) juicer b) stapler                          c) nail clipper

2- A light bulb is an example of a

  1. a) lever b) screw                             c) wedge

3- A fork is an example of a

  1. a) lever b) screw                             c) wedge

4- Toilet paper on a roller is an example of a

  1. a) pulley b) wheel and axle c) inclined plane

5- Label the load, effort, and fulcrum on the illustration below.

 

6-   The tight cap of a bottle can be opened by using a bottle opener. In this
case the bottle opener works as a

  1. a) screw b) wedge                            c) lever

7- If an object is acting as a lever, the force applied on the object is called the

  1. a) load b) effort                              c) fulcrum

8- The point where a lever moves is called the

  1. a) load b) effort                             c) fulcrum

9- A flagpole is an example of a

  1. a) lever b) wheel and axle        c) pulley

10- Roller skates are an example of a

  1. a) lever b) wheel and axle c) inclined plane
Ans: 1. a         2. b       3. c       4. b    5.  fulcrum    effort     load    6. c       7. b           8. c                          9. c      10. b

 

D: ANS THE FOLLOWING QUESRIONS.

Q No.1

Define a machine. Why do we need to use them?

ANS: MACHINE:

           A machine is a device or tool. We use machines to help us do our work more easily and quickly.

Q No.2

How is a simple machine different  from a compound machine?

ANS: A simple machine is made up of one or very few moving parts. A compound machine is made up of more than two simple machines.
Q No.3

Draw a lever and label all three parts in it.

ANS:

 

Q No.4

Where do you see the use of pulleys? Give at least three examples from your daily life.

ANS: We use a pulley in curtain rods, hoisting a flag up a flagpole, and for drawing/shutting window blinds.
Q No.5

How do wheels and axles make work easier?

ANS:Wheel and axles help make movement quick and easy.
Q No.6

How can you say that inclined planes are machines? Give at least three examples from your daily life to support your answer.

ANS: Inclined planes are machines because they make our work easier.

They help us to roll or move objects from lower to higher.

Q No.7

Read the following situations carefully and decide which simple machines should be used to solve these problems.

ANS:

 

U::14 LIGHT        P::  90-92

A: Match each DEFINITION in COLUMN A with the TERMS in COLUMN-B and write the correct Ans in the spaces given below.

COLUMN A COLUMN-B
1- an object that produces its own light A-opaque
2- an object that allows all of the light to pass through it B- translucent

 

3- an object that blocks the light C- transparent
4- an object that allows some of the light to pass through it D- luminous
ANS: 1. D         2.C      3. A      4. B

B Fill in the blanks.

1-A straight line of light coming from a light source is called a——————-

2-An object that gives off its own light is———————————————–

3-An object that does not give off its own light is————————————-

4-An object that allows whole light to pass through it is—————————-

5-An object that allows partial light to pass through it is————————–

6-An object that allows no light to pass through it is called———————–

7-The word solar means—————————

8-The word lunar means—————————

9-The bouncing back of light rays after hitting a smooth surface is called———————————————————–of light.

10- In a——————-eclipse the Moon is completely covered by the shadow of the Earth.

11- When the Moon blocks the sunlight from reaching to the Earth, there is a———————-eclipse.

12 The Moon shines only because it——————the light of the Sun.

ANS: 1. ray 2. luminous 3. non-luminous 4. transparent 5. translucent

6. opaque 7. of the Sun8. of the Moon 9. reflection 10. a lunar   11. a solar 12. reflects

 

C: CIRCLE THE CORRECT ANS.

1-An object that gives off its own light is

  1. a) transparent b) luminous c) non-luminous

2- The objects which allow whole light to pass through them are

  1. a) translucent b) transparent c) opaque

3- Objects which allow partial light to pass through them are

  1. a) translucent b) transparent c) opaque

4- The objects which do not allow light to pass through them are

  1. a) translucent b) transparent c) opaque

5- Which of the following is an example of a luminous object?

  1. a) the Moon b) the Sun c) turned off bulb

6- Which of the following is an example of a non-luminous object?

  1. a) the Moon b) the Sun                                   c) fire

7- Which of the following is an example of a transparent object?

  1. a) a board b) sunglasses c) your textbook

8- Which of the following is an example of a translucent object?

  1. a) your skin b) your bone c) your finger nail

9- Which of the following is a example of an opaque object?

  1. a) waxed paper b) the lens of your eye c) a block of wood

10- Which of the following happens in a lunar eclipse?

  1. A full moon shines.
  2. The Earth’s shadow falls on the Moon.
  3. The Moon’s shadow falls on the Earth.
Ans:1. b    2. b    3. a    4. c    5. b  6. a     7. b     8. c      9. c   10. b                

 

D: ANS THE FOLLOWING QUESRIONS.

Q No.1

What is light?

ANS:

Light is a form of energy.

Q No.2

How does light travel?

ANS:

Light travels in straight lines.

Q No.3

Define the following terms with two examples of each one.

a) Luminous

b) Non-luminous

c) Transparent

d) Translucent

e) Opaque

ANS:

a) Objects which produce their own light are luminous. For example, the Sun, fire and a light bulb.

b) Objects which do not produce their own light are non-luminous. For example, a textbook, wooden desk, eraser, etc.

c) The glass in a windscreen or spectacles is transparent and we are able to see through it.

d) Objects which allow partial light to pass through them are translucent. For example, butter paper and frosted glass.

e) Objects which do not allow any light to pass through them are opaque. We cannot see through them. For example, wood and stone.

Q No.4 Why is the windscreen of a car made up of glass, and not of wood or some metal?
ANS: The windscreen of a car is made of glass, not wood, because glass is transparent and we can see through it clearly. If it were made out of wood or metal, the driver of the car would not be able to see through it and it would be dangerous.
Q No.5

When a thunderstorm occurs, you experience the light first and then the sound. Why?

ANS: When a thunderstorm occurs, we experience light first, then the sound. This is because light travels faster than sound.
Q No.6

Describe solar and lunar eclipses. Draw a well-labelled diagram to show both of the eclipses.

ANS: The pupils should be encouraged to explain the solar and lunar eclipses in their own words. However, if any pupil has difficulty, the pictorial explanation on page 88 of the textbook can be used for guidance.
Q No.7Construct a table in your notebook like the one given below.

Classify the given objects into transparent, opaque and translucent:

cloud, aluminium foil, brick, sunglasses, butter paper, your eyelids, clean air, plastic wrap, frosted glass, cardboard, your eye lens, thin tissue paper

ANS:
OBJECTS TRANSPARENT OPAQUE TRANSLUCENT
cloud, yes yes yes
aluminium foil, yes
brick, yes
sunglasses, yes
butter paper, yes
your eye lids, yes
clean air, yes
plastic wrap, yes
frosted glass yes
cardboard, yes
your eye lens, yes
thin tissue paper yes

 

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