Physics, asked by SHA1NAKumupojyoth, 1 year ago

Light falls from glass to air. Find the angle of incidence for which the angle of deviation is 90o, if refractive index of glass is ​√2.

Answers

Answered by kvnmurty
15
Refractive index of glass = √2
Critical angle = Sin ⁻¹ 1/√2 = 45⁰

When a light ray from glass refracts into air, then angle of deviation is r - i (difference between angle of refraction and angle of incidence).  This cannot be 90 deg. (as i and r are both less than 90 deg).

When a light rays gets totally internally reflected for (i > critical angle) then the angle of deviation can be 90 deg.
Then the angle of reflection = angle of incidence.

    Around the point of incidence we have,  
        4 * angle of incidence + 2 * 90⁰ = 360⁰
         Angle of incidence = 45⁰

As this angle is equal to or more than critical angle, total internal reflection takes place.  Hence. that is the answer.

kvnmurty: click on red heart thanks above pls
Similar questions