NEET2013PhysicsRay OpticsActual
A point source of light is placed 4 m below the surface of water of refractive index 5 / 3 . The minimum diameter of a disc which should be placed over the source on the surface of water to cut-off all light coming out of water is
Options
- A6 m
- B3 m
- C4 m
- D2 m
Correct answer
A. 6 m
Step-by-step solution
Given, i= 1 = 3 5 So, i= 3 4 = r 4 It gives r=3 ~m So, the diameter =6 ~m .