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प्रश्न
What is a shadow? Give a reason for its formation.
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उत्तर
When light falls on an opaque object, light is obstructed and a dark patch on a screen kept behind is called a shadow. This is because light propagates in straight line. If the distance between the object and screen is less, the shadow will be (umbra) dark and smaller.
If the distance is increased shadow will be dim and larger.
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संबंधित प्रश्न
Fill in the blank.
The less dark portion of a shadow is called the .................
Select the correct alternative.
Umbra is a region of
Select the correct alternative.
Penumbra is a region of
Draw a ray diagram to show the formation of umbra and penumbra both. Label the parts umbra and penumbra in your diagram.
In the following diagram, draw rays to form umbra on the screen.

How does the colour of an opaque object affect the colour of the shadow?
Sivarajan placed a meter stick in the playground at 7.00 am in the morning. How will the shadow of the stick at noon look in comparison to the one in the morning
What are the properties of shadow?
What is a shadow? What things are necessary for the formation of a shadow?
Rearrange the boxes given below to make a sentence that helps us understand opaque objects.
| O W S | A K E | O P A Q | U E O | B J E T | T S M |
| S H A D |
The lighter shade of shadow is the ______.
Three torches A, B and C shown in the following figure are switched on one by one. The light from which of the torches will not form a shadow of the ball on the screen.

Correct the following statements.
- The colour of the shadow of an object depends on its colour of the object.
- Transparent objects allow light to pass through them partially.
On a sunny day, does a bird or an aeroplane flying high in the sky cast its shadow on the ground? Under what circumstances can we see their shadow on the ground?
Three identical towels of red, blue and green colour are hanging on a clothes line in the sun. What would be the colour of shadows of these towels?
A student had a ball, a screen and a torch in working condition. He tried to form a shadow of the ball on the screen by placing them at different positions. Sometimes the shadow was not obtained. Explain.
