Question

The angular resolution of 20cm diameter telescope at wavelength 1.2micrometre is?

Answer 1

angular resolution of telescope is given by, $\theta=\frac{1.22\lambda}{d}$

where $\theta$ is angular resolution of telescope, d is diameter of telescope and $\lambda$ is wavelength.

here, d = 20cm = 0.2m , $\lambda=1.2\mu m$ = 1.2 × 10^-6 m

so, angular resolution, $\theta$ = 1.22 × 1.2 × 10^-6/0.2 rad

= 1.22 × 6 × 10^-6 rad

= 7.32 × 10^-6 rad