A point source is placed at a depth 
in a liquid of refractive index is 
. Find the percentage of energy of light that escapes from the liquid. (Assuming 
transmission of emerging light)
Text Solution
Verified by ExpertsA
The portion of light escaping into the air from the liquid will form a cone. As long as the angle of incidence on the liquid - air interface is less than the critical angle, i.e. 
, the light rays will undergo refraction and emerge into the air.
For 
, the light rays will suffer TIR. So, these rays will not emerge into the air.
The portion of light rays emerging into the air from the liquid will form a cone of half angle 
Solid angle contained in this cone is
Percentage of light that escapes from liquid 
Putting values we get
Percentage 
──────────────────────────────────────────────────────────────────────────────────────────
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems