What objective diameter is required for a telescope to just resolve two objects…

PHYSICS · Single correct · A Level · Physics · Astrophysics · Astrophysics

Problem

What objective diameter is required for a telescope to just resolve two objects separated by

0.20\,\text{arc-sec}

when observing

600\,\text{nm}

light?

(1\,\text{arc-sec}=4.85\times10^{-6}\,\text{rad})

(a)

1.50\,\text{m}

(b)

0.75\,\text{m}

(c)

3.7\,\text{m}

(d)

0.62\,\text{m}