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प्रश्न
Answer the following.
How is a shadow formed? Write the conditions required for a shadow to form.
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उत्तर
Whenlightfallsonanopaqueobject, light is obstructed and a dark patch on a screen kept behind is called the shadow. This is because light propagates in a 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.
Conditions Required for a shadow to form are:
- There should be a source of light.
- An opaque object.
- A screen.
- The opaque object is placed between the source of light and the screen.
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संबंधित प्रश्न
Fill in the blank.
The less dark portion of a shadow is called the .................
What is a shadow? Give a reason for its formation.
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.
What is shadow?
What are the essential conditions for the formation of shadow?
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
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.
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?
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.
