Page 238 - text book form physics kssm 2020
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6.1 Refraction of Light
Observe Figure 6.1. What causes the phenomena?
Pencil appears bent in
the water.
Image of pencil appears bent
in the glass block.
Figure 6.1 Phenomena of refraction of light
These phenomena are known as refraction of light. They occur due to the change in
velocity of light when travelling through mediums of different optical densities as shown in
Figure 6.2.
Incident ray
SMART
SMART INFO
Normal
Optical density is not the same
i as density which is defi ned
Air as mass per unit volume.
Glass block For example, the density of
r oil is lower than that of water
Refracted ray causing it to fl oat on the
surface of water. On the other
hand, the optical density of
oil is higher than the optical
density of water.
Emergent ray
Figure 6.2 Refraction of light
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6.1.1
