# Problem: Two light bulbs are 2.0 m apart.From what distance can these light bulbs be marginally resolved by a small telescope with a 5.0 cm-diameter objective lens? Assume that the lens is limited only by diffraction and λ = 600 nm.

###### FREE Expert Solution

The angular resolution limit for two-point sources of light with equal intensity:

$\overline{){\mathbf{∆}}{\mathbf{\theta }}{\mathbf{=}}\frac{\mathbf{1}\mathbf{.}\mathbf{22}\mathbf{\lambda }}{\mathbf{D}}}$, where D is the aperture diameter and Δθ is in radians.

###### Problem Details

Two light bulbs are 2.0 m apart.

From what distance can these light bulbs be marginally resolved by a small telescope with a 5.0 cm-diameter objective lens? Assume that the lens is limited only by diffraction and λ = 600 nm.