Q22 of 38 Page 83

A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water. Will the pencil appear to be bent to the same extent, if instead of water we use liquids like, kerosene or turpentine. Support your answer with reason.

The pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water due to the refraction of light but if we use liquid like kerosene in place of water, then the pencil will bend more than it bend in case of water because the refractive index of kerosene is higher than that of water and is therefore optical denser than water.


So, the pencil will not bend to the same extent due to different refractive indices of different media.


More from this chapter

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20

Identify the device used as a spherical mirror or lens in following cases, when the image formed is virtual and erect in each case.

(a) Object is placed between device and its focus, image formed is enlarged and behind it.


(b) Object is placed between the focus and device, image formed is enlarged and on the same side as that of the object.


(c) Object is placed between infinity and device, image formed is diminished and between focus and optical center on the same side as that of the object.


(d) Object is placed between infinity and device, image formed is diminished and between pole and focus, behind it.

 21

Why does a light ray incident on a rectangular glass slab immersed in any medium emerges parallel to itself? Explain using a diagram.

 23

How is the refractive index of a medium related to the speed of light? Obtain an expression for refractive index of a medium with respect to another in terms of speed of light in these two media?

 24

Refractive index of diamond with respect to glass is 1.6 and absolute refractive index of glass is 1.5. Find out the absolute refractive index of diamond.