Light Shadows and Reflections Solution

Light Shadows and Reflections Solution; Class 6 Science Chapter 11

Contents:

Light Shadows and Reflections Solution: Exercise Questions

1. Rearrange the boxes given below to make a sentence that helps us understand opaque objects.

2. Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:

 Objects Opaque, Transparent or Translucent Luminous or Non-luminous Air Transparent Non-luminous water Transparent Non-luminous A piece of rock Opaque Non-luminous A sheet of aluminium Opaque Non-luminous A mirror Opaque Non-luminous A wooden board Opaque Non-luminous A sheet of polythene Opaque Non-luminous A CD Opaque Non-luminous Smoke Translucent Non-luminous A sheet of plane glass Transparent Non-luminous Fog Translucent Non-luminous A piece of red-hot iron Opaque Luminous An umbrella Opaque Non-luminous A lighted fluorescent tube Opaque Luminous A wall Opaque Non-luminous A sheet of carbon paper Opaque Non-luminous The flame of a gas burner Translucent Luminous 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 Kerosene stove Opaque Luminous Sun Opaque Luminous Firefly Opaque Luminous Moon Opaque 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.

2. Left-Right

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.

3. Periscope

A periscope is a device which makes us see the corner. It is a “Z” shaped device with two mirrors. It is used in the submarines to see above the sea water.

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.