Light Shadows and Reflections Solution; Class 6 Science Chapter 11
Light Shadows and Reflections Solution: Exercise Questions
1. Rearrange the boxes given below to make a sentence that helps us understand opaque objects.
Answer: Opaque objects make shadows.
2. Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:
|Objects||Opaque, Transparent or
|Luminous or Non-luminous|
|A piece of rock||Opaque||Non-luminous|
|A sheet of aluminium||Opaque||Non-luminous|
|A wooden board||Opaque||Non-luminous|
|A sheet of polythene||Opaque||Non-luminous|
|A sheet of plane glass||Transparent||Non-luminous|
|A piece of red-hot iron||Opaque||Luminous|
|A lighted fluorescent tube||Opaque||Luminous|
|A sheet of carbon paper
|The flame of a gas burner
|A sheet of cardboard||Opaque||Non-luminous|
|A lighted torch||Opaque||Luminous|
|A sheet of cellophane||Translucent||Non-luminous|
|A wire mesh||Translucent||Non-luminous|
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?
Answer: Here we need to find an object which is circular from one side and also have a rectangular place.
A cylindrical shape like a pipe, pillar etc has a circular cross-section and a rectangular cross-section. As a result, if we put light towards the circular surface, the shadow formed will be circular. Similarly, if we put light through the length of the pillar or cylinder we will get a rectangular shadow.
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?
Answer: Viewing own image in mirror consist of multiple processes. First, the light falls on our body and reflects towards the mirror. Now, the mirror reflects it to our eyes and we see our own image. In all these steps we need a source of light which can be a sun, a bulb, a candle etc. In a dark room, there is no light. If there is no light then there is no reflection. As a result, we do not see our reflection here.
Light Shadows and Reflections Solution: Suggested Activities.
1. Mirror reflection:
This activity asks us to make a group of friends in a row and check who sees whom.
Observation and explanation: A mirror reflects the light. The angle of reflection here is equal angle made by incident ray. As a result, we see different images by different people with the same mirror.
Our left hand appear as right in the mirror, why?
Answer: A mirror forms an exact replica of us. In this process, we see our image in the inverse position. As a result, our left hand appear as left and left appear as right.
Things to Think About
1. Transparent objects do not make a shadow.
Transparent objects pass all the incident light on the ground. A shadow is a place with no light. As a result, we do not see a shadow with transparent objects like glass.
2. Shadow of an object in coloured light.
Shadow means no light. It does not distinguish between the colour. When we place an opaque object in front of coloured light, the object cast a black shadow and the coloured light forms a coloured background.
Next: Electricity and Circuits Solution.
Fun with Magnets solution.