Answer:
a)It is NOT possible using this telescope, to see the two stars as separate stars
b)[tex]d_{min} =28.466m[/tex]
Explanation:
From the question we are told that:
Diameter of lens,[tex]d = 25 cm \approx 0.25 m[/tex]
Distance from both star [tex]D_f= 2*10^{17} m[/tex]
Distance between both stars [tex]D_b= 6*10^9 m[/tex]
Wavelength of light [tex]\lambda =700 nm \approx 700*10^-9 m[/tex]
Generally the equation for angle subtended by the two stars at the lens is mathematically given by
[tex]\theta=\frac{D_f}{D_b}[/tex]
[tex]\theta=\frac{6*10^9}{2*10^{17}}[/tex]
[tex]\theta=3.0*10^{-8} rad[/tex]
Generally the equation for minimum angular separation of two object is mathematically given by
[tex]\theta_{min} = 1.22*\lambda/d[/tex]
[tex]\theta_{min}= \frac{1.22*700*10^-9}{0.25}[/tex]
[tex]\theta_{min}= 3.416*10^-^6 rad[/tex]
Therefore
[tex]\theta < \theta_{min}[/tex]
[tex]3.0*10^{-8} rad< 3.416*10^-^6 rad[/tex]
It is NOT possible using this telescope, to see the two stars as separate stars
b)
Generally the equation for minimum diameter of the lens is mathematically given by
[tex]d_{min} =\frac{ 1.22*\lambda}{\theta}[/tex]
[tex]d_{min} =\frac{ 1.22*700*10^{-9}}{3*10^{-8}}[/tex]
[tex]d_{min} =28.466m[/tex]
