1
A telescope has an objective lens of 10 cm diameter and is situated at a distance of one kilometer from two objects. The minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is 5000 A, is of the order of
- 0.5 m
- 5 m
- 5 mm
- 5 cm
Answer
(3) 5 mm
Solution
Limit of resolution: = 1.22 D = 1.22 5 10-70.1
= 6.1 10-6 rad
Minimum separation: x = d = 103 6.1 10-6
x = 6.1 10-3 m, i.e. of the order of 5 mm
Answer: (3)
AIPMT 2004