Question

A triangular prism of glass is shown in the figure. A ray incident normally to one face is totally internally reflected. If θ is 45°, then the index of refraction of the glass is ______.

 

Options

• less than 1.41

• equal to 1.41

• greater than 1.41

• None of these

Answer 1

A triangular prism of glass is shown in the figure. A ray incident normally to one face is totally internally reflected. If θ is 45°, then the index of refraction of the glass is greater than 1.41.

Example:

Since the ray is totally internally reflected.

So, 45° > i_c

sin45° > sin i_c

`1/sqrt2 > 1/mu`

⇒ `mu > sqrt2`