STD-6, CHAPTER-14: FABRIC FROM FIBRE, EXERCISE QUESTION ANSWERS

 A.     FILL IN THE BLANKS.

1.      Cotton plants grow well in _____ soil.

Ans: black

2.      Cotton is obtained from the _____ of the cotton plant, called _____.

Ans: fruit, bolls

3.      The body coat of sheep is called the ______.

Ans: fleece

4.      Wool is obtained from the body coat of animals like the ____, _____ or _____.

Ans: sheep, goat, camel

5.      Jute is obtained from the _____ of jute plant.

Ans: bark (stem)

B.      MATCH THE FOLLOWING:

 

1.      Fibres into threads                                       a. dyeing

2.      Thread into fabric                                         b. finishing

3.      Colouring the fabric                                     c. spinning

4.      Making patterns on fabric                          d.  weaving

5.      Making fabric smooth and shiny               e. printing

      Ans:

1.      Fibres into threads                                       c. spinning

2.      Thread into fabric                                        d. weaving

3.      Colouring the fabric                                     a. dyeing

4.      Making patterns on fabric                          e. printing

5.      Making fabric smooth and shiny               b. finishing

 

C.      TICK THE CORRECT OPTION.

 

1.      Which one of these is not a man-made fibre?

(a)   nylon        (b) tereyline           (c) linen        (d) rayon

      Ans: linen

2.      From the following, the only incorrectly matched ‘pair’ is-

(a)   Silk-mulberry              (b) jute-stem         

(c) cotton-seeds                (d) coir-outer covering of coconut

      Ans: cotton-seeds

3.      The process, of pulling and twisting of strands to make a fibre, is known as-

(a)   printing

(b)   spinning

(c)    weaving

(d)   dyeing

       Ans: spinning

4.      ‘Weaving’ is done by using machines called-

(a)   taklis                                    (b)  charkhas

(c)    looms                                   (d)  needles

      Ans: looms

5.      Jute and cotton plants grow well, respectively, in-

(a)   Alluvial, and black, soils

(b)   Black, and alluvial, soils

(c)    Black, and ordinary, soils

(d)   Ordinary, and alluvial, soils

      Ans: alluvial, and black, soils

D.     ANSWER THE FOLLOWING QUESTIONS IN BRIEF.

 

1.      How are clothes important for us?

Ans: Clothes protect ourselves from heat, cold, rain and germs.

2.      Define the term ‘natural fibres’.

Ans: Fibres, which are obtained from natural sources, that is, plants and animals, are called natural fibres.

3.      Give two examples of plant fibres.

Ans: Cotton and jute are two examples of plant fibres.

4.      Name the kind of soil that is suitable for growing jute plants.

Ans: Alluvial soil is suitable for growing jute plants.

5.      Where is coir obtained from?

Ans: Coir is obtained from the outer covering of coconut.

E.      ANSWER THE FOLLOWING QUESTIONS.

 

1.      State the conditions that help in growth of cotton plant.

Ans: i) Black soil is suitable for the growth of cotton plant.

ii) Warm and humid climates, having temperature of over 16⁰ C, provide the most suitable conditions for the growth of the cotton plant.

2.      Why do we need to use ‘fresh soil’ for cultivating jute plant every year? State any three uses of jute.

Ans: i) Jute plant uses up the fertility of the soil to a large extent. Fresh soil is, therefore, needed every year for growing jute plants.

ii) Jute is used for making ropes, gunny bags and mats.

3.      Give the difference between ‘spinning’ and ‘weaving’.

Ans:

Spinning	Weaving
The process of twisting the raw fibres together to make yarn, is called spinning.	The process of making clothes from yarn is called weaving.
Charkha is used for spinning.	Loom is used for weaving.

 

4.      Write, in correct sequence, the names of the steps involved in the production of cloth.

Ans: The steps involved in the production of cloth are,

i) collecting fibres from different sources

ii) spinning

iii) weaving

iv) dyeing

v) printing

vi) finishing

vii) tailoring

5.      Differentiate between natural and synthetic fibres. State any three advantages of synthetic fibres over natural fibres.

Ans:

NATURAL FIBRES	SYNTHETIC FIBRES
Fibres, obtained from natural sources, like plants and animals, are called natural fibres.	Fibres, made from chemicals, that are prepared in factories are called synthetic fibres.
Cotton, Jute, Linen are some examples of natural fibres.	Nylon, terylene and rayon are some examples of synthetic fibres.

 

Three advantages of Synthetic fibres over natural fibres

They are stronger, wrinkle-free, do not shrink and are not spoiled by moths.

STD-6, CHAPTER-13: MAGNETS, EXERCISE QUESTION ANSWERS

 

A.     FILL IN THE BLANKS.

1.      The materials which do not get attracted towards a magnet are called _______.

Ans: non-magnetic substances

2.      The bar magnet is an example of a ______ magnet.

Ans: artificial

3.      Even the smallest piece of a bar magnet has two _____.

Ans: poles

4.      Earth has its magnetic _______ towards its geographical south pole.

Ans: north pole

5.      Magnets have been used for ______ purposes.

Ans: navigation

B.      WRITE TRUE OR FALSE FOR THE FOLLOWING STATEMENTS.

 

1.      Naturally occurring magnets are called loadstones.                                             True

2.      An aluminium foil would get attracted by a magnet.                                           False

3.      Bar magnets have a ‘north seeking’ pole as well as a ‘south seeking’ pole.    True

4.      Two magnetic poles, of the same kind, attract each other.                                False

5.      When two magnets are moved farther apart from each other, the forces, that attract or repel them, tend to become stronger.                                                                                            False

C.      TICK THE CORRECT OPTION.

 

1.      The magnetic material, that was discovered first of all, is-

(a)   iron        (b) steel         (c) loadstone       (d) cobalt

      Ans: loadstone

2.      A magnet can attract-

(a)    a glass object             (b) a flower         (c)  a book         (d) an iron nail

      Ans: an iron nail

3.      A material, that is often used to make a temporary magnet, is-  

(a)   steel       (b)  alnico      (c)   ticanol     (d) soft iron

       Ans: soft iron

4.      When we suspend a bar magnet from a thread, it comes to rest along the–

(a)    North-west direction                                  (b)  east-west direction

(c)     South-west direction                                  (d) north-south direction

      Ans: north-south direction

5.      A device, which generally does not use a magnet, is-

(a)   A CD player                                    

(b)   A telephone

(c)    A geyser

(d)   An electric motor

      Ans: a geyser

D.     ANSWER THE FOLLOWING QUESTIONS IN BRIEF.

 

1.      State any two properties of a bar magnet.

Ans: Two properties of a bar magnet are, attractive property and directive property.

2.      Maximum iron filling stick to the two ends of a bar magnet. Why?

Ans: The magnetic strength is maximum at the two ends of a bar magnet. So, maximum iron fillings stick to the two ends of a bar magnet.

3.      Suppose we bring the north pole of one bar magnet towards the north pole of another freely suspended bar magnet. What are we likely to observe?

Ans: When we bring the north pole of one bar magnet towards the north pole of another freely suspended bar magnet, we will observe that the freely suspended magnet moves away. This is due to the fact that like poles repel each other.

4.      Two magnets X and Y, are placed as shown in the diagram. It is observed that magnet X floats above magnet Y. Give reason for this observation.

Ans: We know that the like poles of two magnets repel each other. Here also, the like poles of both the magnets are facing each other. Hence, the magnets are repelling each other. This is the reason the magnet X is floating above the magnitude Y.

5.      You are given a knitting needle made of steel. How can you make it into a magnet?

Ans: We can turn a knitting needle made of steel into a magnet by moving a bar magnet, along the length of the needle, a large number of times always in the same sense.

E.      ANSWER THE FOLLOWING QUESTIONS.

 

1.      Distinguish between the following:

(a)   Permanent magnet and temporary magnet

Ans: Permanent magnet: These magnets retain their magnetic properties for a longer duration. Permanent magnets can be made using steel, cobalt steel, alnico and ticanol.

Temporary Magnet: These magnets retain their magnetism for a shorter period of time. Electromagnets are a commonly used form of temporary magnets.

(b)   Magnetic and non-magnetic materials

Ans: Magnetic Materials: Materials which get attracted towards a magnet are called as magnetic materials. Examples are cobalt, iron, nickel etc.

Non-magnetic Materials: Materials which do not get attracted towards a magnet are called non-magnetic materials. Examples are wood, plastic etc.

2.      Two bar magnets, ‘P’ and ‘Q’ are kept as shown in the following diagram.

(a) If point ‘c’ represents the south pole of the magnet Q, which point represents the north pole of magnet P?

Ans: As the two magnets are repelling each other, so we can say that the point ‘b’ and ‘c’ represent the like poles. Therefore, point ‘b’ of the magnet ‘P’ is south pole. Thus, the point ‘a’ of the magnet ‘P’ represents the north pole.

(b) What will happen when the end ‘d’, of magnet ‘Q’ is brought towards the end ‘b’ of magnet ‘P’?

Ans: As ‘c’ represents the south pole, so ‘d’ of magnet ‘Q’ is the north pole. So, when the ‘d’ end of ‘Q’ is brought towards the end ‘b’ of magnet ‘P’, they will attract each other.

3.      Describe, in brief, the construction of a compass needle. State its main use.

Ans: ‘The compass’ consists of a magnetic needle pivoted at its centre and free to rotate a horizontal plane. The needle is fitted in a horizontal box having a glass cover. The compass also has a dial with directions marked on it.

The compass needle always points in N-S direction and thus can be used for finding direction.

4.      Draw a labelled diagram to show the ‘proper way of storing two bar magnets’, when they are not in use. State the advantage of such a ‘proper storing’.

Ans: Advantage of proper storage of magnets:

(i) helps in preserving the magnetism in a magnet

(ii) helps in prolonging the life of a magnet

5.      Write the different ways through which magnets can be made to lose their magnetism.

Ans: Magnets can lose their magnetism in the following ways:

(i) by improper storage

(ii) by heating

(iii) by dropping

(iv) by hammering

6.      Anushtha saw a steel clip at the bottom of a very shallow puddle of water. She used a magnet, to take out this clip, without wetting her hands, or the magnet. Describe how she must have done this.

Ans: A magnet can attract an iron object even from a distance. Hence, Anushtha used the attractive property of magnet.

STD-VI, CHAPTER-9, STRUCTURE AND FUNCTION OF THE LIVING ORGANISMS-ANIMALS, EXTRA QUESTION ANSWERS, PART-2

 

1.  What is the function of the nervous system?

 

ANS: The nervous system controls and co-ordinates all the activities of our body.

 

2.  List down the main organs of the nervous system.

 

ANS: The main organs of the nervous system are, brain, spinal cord, nerves and sense organs.

 

3.  Name the most delicate part of the human nervous system.

 

ANS: Brain

 

4.  The brain is protected by the _____.

 

ANS: skull

 

5.  The weight of the human brain is about _____ kg.

 

ANS: 1.35 kg

 

6.  The _____ portion of the brain controls the left part of the body.

 

ANS: right

 

7.  The ______ portion of the brain controls the right part of the body.

 

ANS: left

 

8.  By the age of five, a child’s brain reaches _____ per cent of its full weight.

 

ANS: 90 per cent

 

9.  Name the parts of the human brain.

 

ANS: The parts of the human brain are, cerebrum, cerebellum and medulla.

 

10.  Name the tube-like structure attached to the brain.

 

ANS: spinal cord

 

11.  The length of the spinal cord is about _____ long. 

 

ANS: 50 cm

 

12.  State the function of the spinal cord.

 

ANS: It carries messages from the brain, to all parts of the body, and from the body parts, back to the brain.

 

13.  Name the structure that protects the spinal cord.

 

ANS: back bone (spinal cord)

 

14.  The nervous system consists of billions of _____.

 

ANS: nerve cells

 

15.  The messages (sensations) travel throughout the body as a _____.

 

ANS: small electrical current (nerve impulse)

 

16.  Define nerve impulse.

 

ANS: The electrical signals through which the sensations travel throughout the body are called nerve impulse.

 

17.  Nerves are of ___ types.

 

ANS: two

 

18.  Name the two types of nerves.

 

ANS: The two types of nerves are, sensory nerves and motor nerves.

 

19.  The _____ nerves carry message from sense organs to the brain.

 

ANS: sensory nerves

 

20.  The ____ nerves carry commands from the brain to the muscles.

 

ANS: motor nerves

 

21.  The ____ gives commands to the muscles.

 

ANS: brain

 

22.  Human brains have _____ major sense organs for different senses.

 

ANS: five

 

23.  Name the sense organs of our body.

 

ANS: The sense organs of our body are, nose, eyes, ears, skin and tongue.

 

24.  The nose is sensitive to ____.

 

ANS: smell

 

25.  Our eyes are sensitive to _____.

 

ANS: light (vision)

 

26.  We blink about ____ times on an average.

 

ANS: six

 

27.  Our ears are sensitive to ____.

 

ANS: sound (hearing)

 

28.  The skin is sensitive to ____.

 

ANS: touch

 

29. The tongue is sensitive to _____.

 

ANS: taste

 

30.  There are about _____ taste buds on our tongue.

 

ANS: 10,000

 

31.  State the functions of sense organs.

 

ANS: The sense organs, on receiving a message, in the form of a sensation (smell, touch, taste, vision and sound), send it to the brain through the sensory nerves.

 

32.  State the function of sensory nerves.

 

ANS: The sensory nerves carry message from the sense organs to the brain.

 

33.  State the function of motor nerves.

 

ANS: The motor nerves carry commands from the brain to the muscles.

 

34.  Why is it important to remove waste products from the body?

 

ANS: The waste products if accumulated may become poisonous for the body. So, it is important to remove them.

 

35.  Name the system which helps in removing the waste products from our body.

 

ANS: excretory system

 

36.  How waste products are removed from the body through the skin?

 

ANS: The skin gets rid of water, and excessive salts, in the form of sweat, through the sweat glands, located on the skin.

 

37.  The ____ glands are located on the skin.

 

ANS: sweat glands

 

38.  How the lungs help in removing waste products from the body?

 

ANS: The lungs remove carbon dioxide during respiration.

 

39.  The faeces is eliminated from the rectum, through the ____.

 

ANS: anus

 

40.  ______ is the major waste product of our human body and it is excreted in the form of _______.

 

ANS: urea is the major waste product of our human body and it is excreted in the form of urine.

 

41.  Name the parts of the human urinary system.

 

ANS: The parts of the human urinary system, kidneys, ureters, urinary bladder and urethra.

 

42.  What is urine?

 

ANS: The waste products like urea are removed from the human body in form of a light yellow coloured liquid called urine.

 

43.  There are _____ kidneys in our body.

 

ANS: two

 

44.  State the function of kidney.

 

ANS: Kidney helps to remove waste products like urea and excess water from the body.

 

45.  There are _____ ureters in our body.

 

ANS: two

 

46.  What is the function of ureters?

 

ANS: The ureters carry urine from the kidney to the urinary bladder.

 

47.  Name the part of the urinary system where urine is stored.

 

ANS: urinary bladder

 

48.  About _____ litres of urine are excreted daily.

 

ANS: 1.5 to 2.5 litres

 

49.  The urine from the body gets discharged through the _____.

 

ANS: urethra

 

50.  Name the opening of the human urinary system.

 

ANS: urethra

 

51.  Name the parts which make the human skeleton system.

 

ANS: Skull, backbone, ribs, hip bones and bones of arms and legs make the human skeleton system.

 

52.  State the functions of the skeleton system.

 

ANS: The functions of the skeleton system are as follows,

(i) It gives shape to the body

(ii) It helps in the movement of the body with the help of muscles.

(iii) It protects the soft, delicate, and internal organs of the body from injuries.

 

53.  How the bones are joined together? 

 

ANS: The bones are joined together by ligaments.

 

54.  What are ligaments?

 

ANS: The ligaments are the elastic strands that join bones together.

 

55.  How the muscles are attached to bones?

 

ANS: The muscles are attached to the bones by tendons.

 

56.  What are tendons?

 

ANS: The tendons are the non-elastic tissues that attach muscles to bones.

 

57.  Distinguish between ligaments and tendons.

 

ANS:

Ligaments	Tendons
Ligaments connect bones to bones.	Tendons attach muscles to bones.
These are elastic tissues.	These are non-elastic tissues.

 

58.  How do bones move?

 

ANS: The muscles which are attached to the bones contract and relax. This helps the bones to move.

 

59.  The human skeleton of an adult is made up of ____ bones.

 

ANS: 206

 

60.  The male reproductive system has a pair of _____.

 

ANS: testes

 

61.  Sperms are produced by the _____.

 

ANS: testes

 

62.  The female reproductive system has a pair of ____.

 

ANS: ovaries

 

63.  Eggs are produced by the _____.

 

ANS: ovaries

 

64.  Name the process of fusion of an egg with a sperm.

 

ANS: fertilisation

 

65.  Define fertilisation.

 

ANS: The process of fusion of an egg with a sperm is called as fertilisation.

 

66.  The fertilised egg develops into an ______.

 

ANS: embryo