Discussion Forum



1)

Assuming  human pupil to have radius of 0.25cm and a comfortable viewing distance of 25cm , 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$

Answer:

Option B

Explanation:

 We can write receiving  angle of nacked eye as

2622021414_m37.JPG

$\theta=1.22\frac{\lambda}{D}$

  Where, D is the diameter of eye lens.

    or    $\frac{Y}{25\times10^{-2}}=\frac{1.22\times500\times 10^{-9}}{0.25\times2\times 10^{-2}}$

                  $Y=30\times 10^{-6}m=30\mu m$