question_answer 15)

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:

Classification of objects or materials is given below:  

Object	Object is Transparent /Translucent/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
Mirror	Opaque	Non-luminous
Wooden board	Opaque	Non-luminous
Sheet of polythene	Translucent	Non-luminous
CD	Translucent	Non-luminous
Smoke	Translucent	Non-luminous
Sheet of plane glass	Transparent	Non-luminous
Fog	Translucent	Non-luminous
Piece of red hot iron	Opaque	Luminous
Umbrella	Opaque	Non-luminous
Lighted 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	Luminous
Sheet of cellophane	Transparent	Non-luminous
Wire mesh	Translucent	Non-luminous
Kerosene stove	Opaque	Luminous
Sun	Opaque	Luminous
Firefly	Opaque	Luminous
Moon	Opaque	Non-luminous