NCERT Notes And Solution Class 6 science CHAPTER 11

            

                   Chapter 11

Light, Shadows and Reflections

Class 6 science notes

This chapter about light , shadows and reflections

Luminous objects

Some object that gives out light of its own known as luminous objects. e.g sun, torch

11.1 Transparent, Opaque And Translucence Objects.  

Transparent objects:-
If we can see through an object, it allowing light to pass through it called transparent . Examples:- Glass.

Opaque objects

If we cannot see through an object , it called opaque. Examples :- wood, wall.

Translucent objects

There are some objects through which we can see, but not very clearly. Such objects are known as translucent. Examples :- oily paper.

11.2 What Exactly Are Shadows?

Shadows are formed when an opaque object comes in the path of light.

11.3  A pinhole Camera

Pinhole camera can be made with simple materials and can be used to image the sun and brightly lit objects.

Pinhole camera how to make
How to make a pinhole camera?

Take two boxes so that one can slide into another with no gap in between them.
cut open one slide of each box. On the opposite face of the larger box, make a small hole in the middle. In the smaller box, cut out from the middle a square with a side of about 5 to 6 cm.  Cover this open square in the box with tracing paper. Slide the smaller box inside the larger one with the hole, in such a way that the slide with the tracing paper is inside. Now pinhole camera is ready for use.

11.4  Mirror and Reflections

Mirror - mirror give us clear reflection images of different things.

Reflections:- reflections is the image of something it may be things, person or animals in a mirror or on any reflective surface.

Class 6 science solutionsChapter 11 - Light, shadow and reflections                                  Excercise

Q1. Rearrange the boxes given below to make a sentence that helps us understand opaque objects.
OWS,  AKE,  OPAQ,  UEO  BJEC, TSM, SHAD

ANS:- OPAQUE,OBJECTS,MAKE, SHADOWS.

Q2. 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, lighted torch, a sheet of cellophane, a wire mesh, kerosene stove, sun, firefly, moon.
Ans:-
OPAQUE OBJECTS:- A piece of rock, a sheet of aluminium, a mirror, a wooden board, A CD, 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 card board, a lighted torch, Kerosene stove, sun , fire fly.

TRANSPARENT :-  Air, water, a sheet of plane glass, a sheet of cellophane.

Luminous:-  A piece of red hot iron,  a lighted fluorescent tube, the flame of a gas burner, a lighted torch, kerosene stove, sun, firefly.

Non - Luminous :- A piece of rock, a sheet of aluminium, a mirror, a wooden board, A CD, an umbrella, a wall, a sheet of carbon paper, a sheet of cardboard, air, water, a sheet of plane glass, a sheet of cellophane

Q3. Can you think of creating a shape that would give a circular shadow if held in one way and rectangular shadow if held in another way?
Ans:-

Yes, it can be done let's understand how. When the top of the cylinder faces the sun, then the shadow formed, it will be circular. But when the side of the cylinder faces the sun the shadow becomes will be rectangular.

Q4. 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?
Ans:- No, in a dark room, mirror reflection of image will not form, as light will no fall on the mirror to reflect the image.