You are given an iron strip. How will you make it into a magnet?
A iron strip can be converted into magnets by an experiment:
How is a compass used to find directions?
It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it.
Where are poles of a bar magnet located?
A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located?
A magnet was brought from different directions towards a toy boat that has been floating in water in a tub. Affect observed in each case is stated in Column I. Possible reasons for the observed affects are mentioned in Column II. Match the statements given in Column I with those in Column II.
Column I Column II
Boat gets attracted towards the magnet Boat is fitted with a magnet with north pole towards its head
Boat is not affected by the magnet Boat is fitted with a magnet with south pole towards its head
Boat moves towards the magnet if north Boat has a small magnet fixed along its length
pole of the magnet is brought near its
head
Boat moves away from the magnet Boat is made of magnetic material when north pole is brought near its head
Boat floats without changing its direction Boat is made up non-magnetic material
Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indicates the resulting action between them for each situation. Fill in the blanks.
Column I Column II
N - N _________
N - _________ Attraction
S - N _________
_________ - S Repulstion
Write any two properties of a magnet.
Fill in the blanks in the following
(i) Artificial magnets are made in different shapes such as __________, __________ and ____________.
(ii) The Materials which are attracted towards a magnet are called________.
(iii) Paper is not a ______ material.
(iv) In olden days, sailors used to find direction by suspending a piece of ___________.
(v) A magnet always has __________ poles.
State whether the following statements are true or false
(i) A cylindrical magnet has only one pole.
(ii) Artificial magnets were discovered in Greece.
(iii) Similar poles of a magnet repel each other.
(iv) Maximum iron filings stick in the middle of a bar magnet when it is brought near them.
(v) Bar magnets always point towards North-South direction.
(vi) A compass can be used to find East-West direction at any place.
(vii) Rubber is a magnetic material.
(a) Which kind of garbage is not converted into compost by the redworms?
(b) Have you seen any other organism besides redworms, in your pit? If yes, try to find out their names. Draw pictures of these.
Rearrange the boxes given below to make a sentence that helps us understand opaque objects.
To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?
Do you find that all living beings need the same kind of food?
Name the major nutrients in our food.
Classify the following fibres as natural or synthetic:
nylon, wool, cotton, silk, polyester, jute
Name five objects which can be made from wood.
Why do we need to separate different components of a mixture? Give two examples.
Correct the following statements and rewrite them in your notebook.
(a) Stem absorbs water and minerals from the soil.
(b) Leaves hold the plant upright.
(c) Roots conduct water to the leaves.
(d) The number of petals and sepals in a flower is always equal.
(e) If the sepals of a flower are joined together, its petals are also joined together.
(f) If the petals of a flower are joined together, then the pistil is joined to the petal.
Fill in the blanks:
(a) Joints of the bones help in the ——————— of the body.
(b) A combination of bones and cartilages forms the _______ of the body.
(c) The bones at the elbow are joined by a ______________________ joint.
(d) The contraction of the _____________ pulls the bones during movement.
To clean their spectacles, people often breathe out on glasses to make them wet. Explain why the glasses become wet.
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
In a completely dark room, if you hold up a mirror in front of you, will you see a reflection of yourself in the mirror?
From which parts of the plant cotton and jute are obtained?
What is the composition of air?
Which of the following statements are “true” ?
(a) Water vapour is present in air only during the monsoon. ( )
(b) Water evaporates into air from oceans, rivers and lakes but not from the soil.( )
(c) The process of water changing into its vapour, is called evaporation.( )
(d) The evaporation of water takes place only in sunlight.( )
(e) Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.( )
Fill up the blanks
(a) The presence of specific features, which enable a plant or an animal to live in a particular habitat, is called .
(b) The habitats of the plants and animals that live on land are called habitat.
(c) The habitats of plants and animals that live in water are called habitat.
(d) Soil, water and air are the ———— factors of a habitat.
(e) Changes in our surroundings that make us respond to them, are called .
Which of the things in the following list are nonliving?
Plough, Mushroom, Sewing machine, Radio, Boat, Water hyacinth, Earthworm
Classify the following fibres as natural or synthetic:
nylon, wool, cotton, silk, polyester, jute
Explain the process of making yarn from fibre.