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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 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
Draw a ray diagram to show the formation of umbra alone.
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 umbra on the screen.

In the following diagram, draw rays to form a penumbra on the screen.

How does the colour of an opaque object affect the colour of the shadow?
What are the parts of shadow?
What are the properties of shadow?
______ is always against, opposite side of light source.
The ______ is the darkest part 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.

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.
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?
