Diameter of human eye lens is 2 mm. What will be the minimum distance between two points to resolve them, which are situated at a distance of 50 metre from the eye? The wavelength of light is 5000 Å.
- 2.32 m
- 4.28 mm
- 1.25 cm
- 12.48 cm
Answer
(3) 1.25 cm
Solution
Limiting angle of resolution of the eye:
D
= 5000 10-102 10-3
= 2.5 10-4 rad
Minimum separation of the two points at distance x = 50 m:
y = x
= 50 2.5 10-4
= 1.25 10-2 m
∴ y = 1.25 cm
Answer: (3)