Question

A star is emitting light at the wavelength of 5000 Å. Determine the limit of resolution of a telescope having an objective of a diameter of 200 inch.

Answer 1

Given: λ = 5000 Å = 5 × 10^-7 m

D = 200 × 2.54 cm = 5.08 m

θ = `(1.22 lambda)/"D"`

`= (1.22 xx 5 xx 10^-7)/5.08`

= 1.2 × 10^-7 rad