How are Shadows Formed?

Hold your hand between a lighted torch and the wall. What do you observe? You will observe that a dark area in the shape of your hand is formed on the wall. This dark area is called a shadow.

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Experiment-A

Hold a steel plate or cardboard in front of your eyes. Can you see through them? No, we cannot. The objects which do not allow the light to pass through them are called opaque objects. Make a light of some opaque objects you have know.

Experiment-B

Apply some oil on a white sheet of paper. Hold it in front of you eyes. Can you see through it? Hold a lighted torch on one side of the paper. You will find that some light passes through it. Repeat the same with a tracing paper. These things allow the light to pass through them partially. They are called translucent objects.

Experiment-C

Hold a glass sheet in front of your eyes. Can you see the objects through it? Does it allow the light to pass through it? Yes it allows the light to pass through it. Such objects, which allow the light to pass through them, are called transparent objects.

Shadows

i-1

Hold your hand between a lighted torch and the wall. What do you observe? You will observe that a dark area in the shape of your hand is formed on the wall. This dark area is called a shadow. Move your hand towards or away from the torch. Observe the changes in the sizes of the shadows. Observe the changes in the sizes of the shadows. All opaque objects cast their shadows whereas translucent and transparent object do not.

You can make interesting shadows using your hands and fingers. By folding your hands in different patterns you can make different types of shadows on the wall. You can make shadows that look like the head of a duck or a dog.

Shadows formation

 Experiment-2

Light a candle and suspend a small ball at a little distance from it. Observe its shadow on the wall. Move the ball a little and change its distance from the burning candle. Observe the changes in the sizes of its shadows. Now replace the ball by a glass sheet. What do you observe?

Light rays always travel in straight lines. When they come across the opaque objects they form shadows because they cannot pass through the opaque objects. When a glass sheet is used instead of a ball the light passes through it and shadow is not formed because it is a transparent object.

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3 Responses to “How are Shadows Formed?”
  1. radha lakshmi Says...

    On July 12, 2009 at 4:52 am

    sun and earth between two a great relation is there.


  2. MassterGee Says...

    On July 13, 2009 at 8:39 pm

    I couldn’t find a lit torch… Sorry.


  3. Right Says...

    On December 5, 2010 at 9:04 am

    What? I didn’t get any of that..


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