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Assuming human pupil to have a radius of...

Assuming human pupil to have a radius of 0.25 cm and a comfortable viewing distance of 25 cm, the minimum separation between two objects that human eye can resolve at 500 nm wavelength is

A

1 `mu`m

B

30`mu`m

C

`100 mu m`

D

`300 mu`m

Text Solution

Verified by Experts

Diameter, d = `0.25 xx 2 = 0.5 cm = 0.005 m`
D = 25 cm = 0.25 m
`lambda = 500 nm = 5xx 10^(-7)` m
Angular resolution, `Delta theta = (1.22lambda)/(d)`
If the required minimum separation is `Delta`x.
`Delta theta = (Deltax)/(D)'`
`therefore " " Deltax = D Delta theta = 0.25 xx (1.22xx(5xx10^(-7)))/(0.005)`
` = 30.5 xx 10^(-6) m = 30.5 mu m approx 30 mu m `
The option (B) is correct.
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