What is a shadow? How does the colour of an opaque object affect the colour of the shadow?ДЄns: Shadow is the dark area behind any opaque object where the light cannot pass through. (b) By placing butter paper on the glass sheet. (a) By applying a thin layer of oil on the glass sheet. How will you convert a glass sheet into a translucent sheet?ДЄns: There are a couple of ways to convert a glass sheet into a translucent sheet: (5) Size is same as that of the object size can be smaller or larger (4) Image can be straight or inverted shadow is not inverted Shadows are vague and donвЂ™t provide any information (3) Image provides a lot of information like colour, shape, etc. (2) Images can be seen when reflected light approaches observerвЂ™s eyeNo light approaches observerвЂ™s eye (1) It is formed by reflected raysIt is formed when no light is allowed to pass through the object, Write the differences between a shadow and an image. The opaque object should be placed in between the source of light and the screen.ДЄns: When light rays after striking the smooth and shiny surface return to the same medium, this phenomenon is called the reflection of light.

(2) Source of light and a screen is needed for the formation of shadow. What are the essential conditions for the formation of shadow?ДЄns: (1) The object should be opaque where light cannot pass through. Draw a diagram to illustrate the formation of umbra and penumbra Example: hot filament in an electric bulb.ДЄns: When light cannot pass through an opaque object, a dark region is formed behind the object called a shadow. What is an incandescent body? Give example.ДЄns: The bodies which emit light when a very high temperature heat is applied to them are called incandescent bodies. Example: earth, blackboard, moon.ДЄns: Moon is a non-luminous body because it only reflects the light from the sun falling on its surface. The bodies which are not able to emit light but are visible only when they reflect light produced by the luminous objects are called non-luminous bodies. Example: Stars, burning candle, sun, etc. What is the difference between a luminous and a non-luminous body?ДЄns: The bodies which have its own source of energy to emit light are called luminous bodies. Is the moon luminous or non-luminous body?ДЄns: The dark shadow region which falls behind the object where no light enters is called Umbra.ДЄns: Lightray travels in a straight line.ДЄns: Sun and stars are some of the natural sources of light.ДЄns: Shadow is the dark area behind any opaque object where the light cannot pass through.ДЄns: The partially shaded region which is less dark than the umbra, behind any opaque object is known as Penumbra. 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?ДЄns: No, in a completely dark room, there wonвЂ™t be any light in the room, so there wonвЂ™t be any reflection of light and no image will be formed on the mirror. How would you create a circular shadow if held in one way and a rectangular shape shadow held in another way, with the object?ДЄns: Yes, there are many objects like a cylinder and a circular disc, which would give a circular shadow if held in one way and a rectangular shadow if held in another way.

Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:ДЄir, water, a piece of rock, a sheet of aluminum, a wooden board, a sheet of polythene, a sheet of cellophane, a CD, smoke, a sheet of plane glass, fog, a piece of red hot iron, an umbrella, a lighted fluorescent tube, a wall the fame of a gas burner, a sheet of cardboard, a lighted torch, a wire mesh, a mirror, kerosene stove, sun, firefly, moon, a sheet of carbon paper. NCERT Solution Class 6 Science Chapter вЂ“ 11 Light Shadow and Reflection

Torch stack