Question

A paper, with two marks having separation d, is
held normal to the line of sight of an observer at
a distance of 50 m. The diameter of the eye-lens
of the observer is 2 mm. Which of the following
is the least value of d, so that the marks can be
seen as separate ? The mean wavelength of
visible light may be taken as 5000 Å
(a) 1.25 m (b) 12.5 cm
(c) 1.25 cm (d) 2.5 mm

Answer 1

Answer:

the mean wave length of visible light is 2.5 mm