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प्रश्न
Select the correct alternative.
Penumbra is a region of
पर्याय
complete darkness
complete brightness
partial brightness
none of the above
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उत्तर
partial brightness
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संबंधित प्रश्न
Select the correct alternative.
Umbra is a region of
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?
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.

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?
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
The ______ is the darkest part of a 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?
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.
