NCERT Solutions For Class 6 Science Chapter – 11
Q1. Rearrange the boxes given below to make a sentences that helps us understand opaque objects.
Answer:-
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 , a lighted torch , a sheet of cellophane , a wire mesh , kerosene stove , sun , firefly , moon.
Answer:-
| Objects | Object is Transparent/transclucent/Opaque | Object is Luminous/ Non – Luminous |
| Air | Transparent | Non – luminous |
| Water | Transparent | Non – luminous |
| Piece of rock | Opaque | Non -luminous |
| Sheet of aluminium | Opaque | Non -luminous |
| Minor | Opaque | Non -luminous |
| Wooden board | Opaque | Non -luminous |
| Sheet of all polythene | Translucent | Non -luminous |
| CD | Translucent | Non -luminous |
| Smoke | Translucent | Non -luminous |
| Sheet of plane | Translucent | Non -luminous |
| Fog | Translucent | Non -luminous |
| Piece of red hot iron | Opaque | Luminous |
| Umbrella | Opaque | Non -luminous |
| Lighted of fluorescent tube | Opaque | Luminous |
| Wall | Opaque | Non -luminous |
| Sheet of carbon paper | Opaque | Non -luminous |
| Flame of a gas burner | Translucent | Luminous |
| Sheet of cardboard | Opaque | Non -luminous |
| Lighted Torch | Opaque | Non -luminous |
| Sheet of cellophone | Translucent | Non -luminous |
| Wire mesh | Translucent | Non -luminous |
| Kerosene stove | Opaque | Luminous |
| Sun | Opaque | Luminous |
| Firefly | Opaque | Luminous |
| Moon | Opaque | Non -luminous |
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 ?
Answer:-
When a cylinder is held in sunlight, then a circular shadow or a rectangular shadow can be obtained depending on its orientation related to the Sun.
When the top of the cylinder faces the sun, then the shadow formed is circular . On the other hand , when the side of the cylinder faces the sun, then the shadow formed is 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 ?
Answer:-
An image is formed due to reflection of light by a plane mirror. In a completely dark room, there is no light present in the room. Thus , no reflection of light takes place by the mirror placed in the room. Hence, no image will get formed by a mirror in a completely dark room.