Page 8 - 10-phy-12 Geometrical Optics

8. Adjust the position of the needle to remove the

parallax between the tip of the needle and its

image again. i. How will the refractive
index be affected using
9. Measure the distance h2 between the position more amount of
of needle B to the surface of the liquid O using water?

plumb line.

10. Determine the refractive index n using ii. Explain why the index
formula
of refraction of air is

n = O A = h1 smaller than the index
O B h2 of refraction of a solid.

11. Repeat the experiment by changing the mirror
and take the mean value of n.

No. of Approximate Distance Distance between Refractive index
Obs. focal length f between needle needle & water
n = h1
Observations cm & mirror surface h2
and Data OA = h1
Processing OB = h2
Conclusions cm cm

1

2

3

Average refractive index n = ……. cm

Eye

Post Lab. A girl throws a coin into the pond. It sinks to the bottom
Activities I. On the diagram, draw the path of the ray of light
from the coin to her eyes.

______________________________

______________________________ Coin
______________________________

ii. What happens to light when it passes from water into air?.
____________________________________________________

____________________________________________________

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