Question

Two stars are situated at a distance of 8 light years from the earth. These are to be just resolved by a telescope of diameter 0.25 m. If the wavelength of light used is 5000 Å, then the distance between the stars must be
A. `3 xx10^(10) m`
B. `3.35 xx10^(11) m`
C. `1.35 xx10^(11) m`
D. `4.32 xx10^(10) m`

Answer 1

Correct Answer - C
`d=(1.22lamda xx)/(D)=(1.22xx5xx10^(-7)xx8xx10^(16))/(0.25)`
`=1.95xx10^(11)m`