Page 99 - ScienceStd4

2. Observe how the pencil appears.

3. Pour water from the jug into the bowl or beaker until it

reaches half full, as shown in Figure 12.
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4. Observe again the appearance of the pencil in the bowl

or beaker after adding the water. What differences do you
notice in the appearance of the pencil before and after
adding the water?

Results

The pencil appeared to be bent at the water surface due to the
refraction of light.

Conclusion

This experiment shows that light rays bend when they move
from one transparent medium to another.

Uses of light energy

Light energy can be used for various purposes as shown in

Table 4.

Table 4: Uses of light energy
Picture Explanation

Vision: Light helps us see things.
Without light, we would not be
able to see colours, shapes or
objects around us.

Photosynthesis: Plants use light
energy from the sun to make

their food.

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