1. Keywords :
1. Keywords :
SOLUTIONS.
1. LUMINOUS :- The object which emit light itself is called, Luminous Objects.
2. MIRROR :- A Mirror forms a virtual and erect image of the same size as that of the objects, and the image is laterally inverted called mirror.
3. OPAQUE :- Objects through which we can not see are opaque objects. Opaque objects do not allow light to pass through them. For example :- Stone, Metals
4. PINHOLE CAMERA :- It is a simple image formation device, it consists of a box with completely dark inner walls.
5. REFLECTION :- The bouncing back of lights from the surface of an objects is called, "Reflection"
6. SHADOW :- Shadow are formed when an opaque objects comes in the path of light. Example eclips is shadow which found in nature.
7. TRANSLUCENT :- Objects through which we can see but not clearly are Translucent objects. Translucent objects allow some light to pass through them. For example Butter paper, Plastic sheet
8. TRANSPARENT :- Object through which we can see are transparent objects. Transparent objects allow light to pass through them.For example water and glass.
2. 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, the moon.
2. 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, the moon.
Solution :-
Opaque: 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
Transparent: Air, water, and a sheet of plane glass
Translucent: A sheet of polythene, smoke, fog, a sheet of cellophane, and a wire mesh
Luminous: A piece of red hot iron, a lighted fluorescent tube, the flame of a gas burner, a lighted torch, sun, firefly, kerosene stove
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, an umbrella, a wall, a sheet of carbon paper, a sheet of cardboard, a sheet of cellophane, a wire mesh, moon.
3. 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?
3. 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?
Solution :-
No, in a dark room, a mirror reflection of the image will not be shown as the light will not fall on the mirror to reflect the image due to darkness
Also Read: Chapter 12: Electricity and Circuits
