Question

The minimum angular separation between two stars is 4 × 10⁻⁶ rad, if telescope is used to observe them with an objective of aperture 16 cm. Find the wavelength of light used.

Answer 1

dθ = 4 × 10⁻⁶ rad, a = 16 cm = 16 × 10⁻² m

The wavelength of light used is 5246 Å.