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प्रश्न
Why is it that the birds flying in the sky do not cast their shadow on the earth?
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उत्तर
We do not see the shadow of a bird flying high up in the air because in their shadow, the umbra is absent and the penumbra is too large and too faint that it is not visible as the distance of screen (i.e. earth) is very large from the object (i.e. bird).
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संबंधित प्रश्न
Fill in the blank.
The less dark portion of a shadow is called the .................
Select the correct alternative.
Penumbra is a region of
State two differences between an umbra and a penumbra.
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 a penumbra on the screen.

Tick the correct answer.
Umbra is a region of
What is shadow?
What is penumbra?
When does a shadow form?
What do we need in order to see a shadow?
What are the properties of 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 ______ is the darkest part of a shadow.
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.

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?
A football match is being played at night in a stadium with flood lights ON. You can see the shadow of a football kept at the ground but cannot see its shadow when it is kicked high in the air. Explain.
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.
