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प्रश्न
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
उत्तर
We can see the shadow of a football lying on the ground because the ground acts as a screen for it. However, when the football is kicked high, the ground, which is acting as a screen is away from the football, hence no shadow of the football will be formed on the ground.
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संबंधित प्रश्न
Fill in the blank.
The darkest portion of a shadow is called the ................
Draw a ray diagram to show the formation of the shadow of an opaque object by a point source of light. How is the size of shadow affected if the screen is moved away from the object?
State two differences between an umbra and a penumbra.
Draw a ray diagram to show the formation of umbra alone.
State the conditions when only the penumbra of an opaque object is obtained on the screen.
Why is it that the birds flying in the sky do not cast their shadow on the earth?
Answer the following.
How is a shadow formed? Write the conditions required for a shadow to form.
What is penumbra?
When does a shadow form?
What are the essential conditions for the formation of shadow?
How does the colour of an opaque object affect the colour of the shadow?
What are the parts 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.
Correct the following statements.
- The color of the shadow of an object depends on the color 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?
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?
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.
