These AP 6th Class Science Important Questions 11th Lesson Shadows – Images will help students prepare well for the exams.
AP State Syllabus 7th Class Physical Science 11th Lesson Important Questions and Answers Shadows – Images
6th Class Science 11th Lesson Shadows – Images 2 Mark Important Questions and Answers
What is the need of light?
We need light to see objects.
What is light of source?
Substance which gives light is known as a source of light.
When the shadows are formed?
Shadows are formed when opaque objects obstruct the path of light.
What we need to obtain shadow?
In addition to light and object we also need a screen to obtain the shadow of an opaque object.
Are you guess the colour of object by its shadow?
The colour of objects cannot be determined by looking at their shadows.
How the light travels?
Light travels in a straight line.
When the light reflected?
Light gets reflected when it falls on any object.
How do the people know that light travels in a straight line?
People came to an understanding that light travels in a straight line by observing the shapes of shadows.
Why am I not able to see the objects clearly when it gets dark?
In the dark light is not sufficient to see the objects.
Why am I not able to see the objects when the power goes off?
When the power goes off light is absent. So we can’t see the objects.
How are we able to see the objects in the presence of light?
The light reflects eyes that fell on objects. So we are able to see the objects.
Why are we not able to see the objects in the absence of light?
Light is the source of visible since. So without light, we can’t see anything.
What are the conditions to form a shadow?
We need a source of light and an opaque object and a screen to get a shadow.
How in ancient days, people came to an understanding that light travels in a straight line?
In ancient days, by observing the shapes of shadows people came to an understanding that light travels in a straight line.
6th Class Science 11th Lesson Shadows – Images 4 Mark Important Questions and Answers
How can we see the objects?
- When we put on the bulb, light falls on the object, bounces from the object and reaches us.
- We can see an object only when light falls on it and bounces back to our eyes.
- The object is visible when there is no obstruction between your eyes and the object.
- It means light travels in straight lines.
How do you classify the objects according to light traveling through them?
- The substances like paper, plank, wood, iron, etc. don’t allow light to pass through them. These objects form shadows. These are called opaque substances.
- The substances like glass and air allow light to pass through them and hence we don’t get their shadows. Such substances are called transparent substances.
- The substances such as polyethylene cover and oily paper partially allow the light to pass through them. Their shadows are unclear. These substances.
Write about shadow puppet?
- Shadow puppetry is one of our traditional recreational activities.
- In this, some puppets are used to form shadows on a screen and a story is narrated with the help of these shadows.
- By using this art old epics like Ramayana and Maha Bharat were played.
- Now a days this old art losses its glow.
Write the difference between opaque and transperent substances?
Opaque: An object which does not allow light to pass through it and you are not able to see the objects behind your opaque material.
Transparent: An object that allows light to pass through it and you can see the objects behind your transparent material.
Vivek said that light and object are enough to form a shadow? Are you agree with him?
No. I can’t agree with this statement. I understand that only light and an opaque object are not enough to form the shadow of an object. In addition to these, we need a screen.
Can we guess the object by observing its shadow?
- Mostly we guess the object by observing its shadow.
- But it is not always possible.
- Sometimes the shadow may differ from the shape of the object.
- Because of light source position and shape of the object.
What is a pinhole camera?
It is a small instrument that works on the light.
With this camera, we can observe a big object through a pinhole.
On the screen, it forms a little reverse image without a lance.
The nature of the straight-line motion of light can also be understood by this one.
Look at a tree through the pinhole camera. What do you see?
When I observe the tree in the pinhole camera
- the image is small.
- it is inverted on the screen.
- it is colorful.
- and appear near to me.
Predict what would happen if we make two pin-holes in the camera?
- If we make two pin-holes in the camera I predict that images are not clear.
- But it is a wonder that it forms two images, both are clear.
We see our faces in the mirror every day. Is the picture in the mirror a shadow or an image? How did you decide that?
- The picture in the mirror is an image.
- We know that shadows are not colored but an image has colors that are the same as that of the object.
- A shadow shows only the outline of the object but an image shows the complete object as it is, just like a photograph.
- The picture in the mirror has color and shows a complete object. So its an imaged
Can you show the difference between a shadow and an image through a drawing?
Yes, we can show the difference between shadows and images through a drawing.
- In images, we can use color and draw the whole picture.
- Whereas in shadows we draw only outline and fill with black.
6th Class Science 11th Lesson Shadows – Images 8 Mark Important Questions and Answers
How do you prove that screen is necessary to form shadow?
Aim: To prove that screen is necessary to form shadow.
Materials: Torch, leaf, darkroom, drawing sheet, or plank.
- Do this activity in a dark room with a torch and a leaf.
- Focus the light on the leaf with a torch.
- Keep the distance about 30 cm between the leaf and the torch.
- Now the shadow is formed in the wall.
- Now put the torch under the leaf at a distance of about 30cm.
- Now the shadow is formed on the roof.
- Do the same activity, in the open air (outside) at night.
- Now we can’t find any shadow outside.
- Place a drawing sheet or a plank at a distance of 1 m. above
- Now we can find a shadow on the drawing sheet.
- It means the screen is needed to form shadows.
Conclusion: It is proved that screen is needed to form shadows.
Write the process of making a pinhole camera? (Activity – 6)
Aim: Making a pin-hole camera.
Materials: A PVC pipe, about 8 cm in diameter and of length 30 cm.
A PVC pipe, about 7 cm in diameter and of length 20 cm.
One black drawing sheet. Oil -1 ml, two rubber bands, a pin, and A4 Sheet. (If you cannot get PVC pipes, take a thick sheet of paper and roll it to form tubes. The diameter and length of the tubes should be the same as that given for the pipes.)
- Cut a piece of black paper and put it like a cap at one end of the big pvc pipe and fix it with a rubber band as shown in the figure.
- Put the white paper like a cap at one end of the thinner PVC pipe.
- Fix it with a rubber band, now make a hole in the middle of the black paper cap with the help of a pin.
- Put 2 to 3 drops of oil on the white paper cap so that it becomes translucent.
- Insert the thin pipe into the big pipe. Your pinhole camera is ready
- Arrange a lighted candle in front of the pinhole of the camera.
- Move the thinner pipe forward and backward to get a clear picture of the candle on the screen of the thin pipe.
- This picture is to be observed from the back of the thin pipe.
Observation: The flame of the candle appears inverted on the screen. This is not the shadow of the candle. It is its image.
Why the image in the pinhole camera is inverted?
- The light from the candle travels straight in all directions from each point of the flame of the candle.
- But only the light coming in some particular directions can enter into the camera through its pin-hole.
- The light that comes from the point at the top of the flame goes straight towards the bottom of the screen.
- And the light that comes from the point at the bottom of the flame goes straight towards the top of the screen.
- In this way, the light coming in a particular direction from each point of the flame will be able to enter into the pin-hole.
- And light going in other directions is blocked by the black sheet.
- This leads to the formation of an inverted image.
- The formation of an inverted image on the screen of the pinhole camera explains that light travels in a straight line.