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Chapter 11: Light, Shadows and Reflections, Qn 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 aluminum, 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., 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, a sheet of plane glass., Translucent: A sheet of polythene, smoke, fog, a sheet of cellophane, 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., Qn 3. 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?, Yes,, Circular and rectangular shadow formation, Qn 4. 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?, 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.