Question

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 Å, is of the order of(a) 5 cm(b) 0.5 m(c) 5 m(d) 5 mm

Answer 1

the answer is 5,m option c

Answer 2

Answer:

D) 5mm

Explanation:

Objective lens = 10cm (Given)

Distance = 1km (Given)

Minimum distance between two objects = 5000 Å (Given)

θ = x/d

x/1000 = 1.22λ/a

or = 1.22×d/a

or = 1.22×5000×10−10×10³/10×10−2

= x = 1.22×5×10-3

= 6.1m

Thus, the minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is 5000 Å, is of the order of 5mm