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A cubical transparent slab is used as a ...

A cubical transparent slab is used as a paper weight. What should be the minimum refractive index of the material of the slab so that letters below it are not visible from any of its vertical faces.

A

`sqrt(2)`

B

`sqrt(3)`

C

`sqrt(5)`

D

`sqrt(5)//sqrt(3)`

Text Solution

Verified by Experts

Use the concept of total internal reflection.
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