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प्रश्न
State two differences between an umbra and a penumbra.
उत्तर
Umbra
- It is the portion of shadow where no light reaches from the source of light due to the opaque object.
- It is completely dark.
Penumbra
- It is the portion of shadow where a portion of light from the source of light reaches the shadow even in the presence of the opaque object in between them.
- It is not completely dark but is dim (or less bright).
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संबंधित प्रश्न
Fill in the blank.
The darkest portion of a shadow is called the ................
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
What is a shadow? Give a reason for its formation.
In the following diagram, draw rays to form umbra on the screen.
State the conditions when only the penumbra of an opaque object is obtained on the screen.
Tick the correct answer.
Umbra is a region of
What is penumbra?
When does a shadow form?
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 |
______ is always against, opposite side of light source.
The lighter shade of shadow is the ______.
Three torches A, B, and C shown in Fig. 11.7 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 torch is placed at two different positions A and B, one by one, as shown in Fig. 11.9.
The shape of the shadow obtained in two positions is shown in Fig. 11.10
Match the position of the torch and shape of the shadow of the ball.
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?
