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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
Select the correct alternative.
Umbra is a region of
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?
In the following diagram, draw rays to form umbra on the screen.

Tick the correct answer.
Umbra is a region of
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
What is a shadow? What things are necessary for the formation of a shadow?
Which of the following can never form a circular shadow?
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 torch is placed at two different positions A and B, one by one, as shown in the following figure.

The shape of the shadow obtained in two positions is shown in the following figure.

Match the position of the torch and shape of the shadow of the ball.
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.
