Class 6 Science - Chapter Light, Shadows and Reflections NCERT Solutions | In a completely dark room, if you hold u

Can you think of creating a shape that would give a circular shadow if held in one way and a rectangular shadow if held in another way?

Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:

Air, water, a piece of rock, a sheet of aluminium, a mirror, a wooden board, a sheet of polythene, a CD, smoke, a sheet of plane glass, fog, a piece of red hot
iron, an umbrella, a lighted fluorescent tube, a wall, a sheet of carbon paper, the flame of a gas burner, a sheet of cardboard, a lighted torch, a sheet of cellophane, a wire mesh, kerosene stove, sun, firefly, moon.

Rearrange the boxes given below to make a sentence that helps us understand opaque objects.

(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.

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.

What is a habitat?

How do plants and animals help each other in the exchange of gases in the atmosphere?

List five activities that are possible due to the presence of air.

Name two flowers, each with joined and separated sepals.

Give two examples of periodic motion.

The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why?

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

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

Do you think it is better to use compost instead of chemical fertilisers? Why?

How is a compass used to find directions?

The layer of air around the earth is known as ___________.