Question

The angular separation of a converging lens 3 cm in diameter and a focal length of 20 cm is .......

assume λ ( 550 nm  )

Answer 1

Diameter, $D=3 \space cm=3\times10^{-2}\space m$

$\lambda=550\space nm=550\times10^{-9}\space m$

Angular Separation $=\dfrac{1.22\lambda}{D}=\dfrac{1.22\times550\times10^{-9}}{3\times10^{-2}}$

$=2.24\times10^{-5}\space rad$