There is a small source of light at some depth below the surface of water (refractive index = 4/3) in a tank of large cross sectional surface area. Neglecting any reflection from the bottom and absorption by water, percentage of light that emerges out of surface is (nearly) :
[Use the fact that surface area of a spherical cap of height h and radius of curvature r is 2 π rh]
Text Solution
Verified by ExpertsThe correct answer is:
C
sin β = 
, cos β = 
Solid angle d Ω = 2 π R 2 (1 – cos β )
Percentage of light = 
× 100
= 
× 100 = 
× 100 ≈ 17%
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
A car is fitted with a convex side–view mirror of focal length 20 cm. A second car 2.8 m behind the…
A beaker contains water up to a height h 1 and kerosene of height h 2 above water so that the total…
When monochromatic red light is used instead of blue light in a convex lens, its focal length will :
An object 2.4 m in front of a lens forms a sharp image on a film 12 cm behind the lens. A glass pla…
Diameter of a plano - convex lens is 6 cm and thickness at the centre is 3 mm. If speed of light in…
The graph between angle of deviation ( δ ) and angle of incidence (i) for a triangular prism is rep…