Question

The aperture of the largest telescope in the world
is 5m. If the separation between the moon and
the earth is 4×105 km and the wavelength of
visible light is 5000 Å, then the minimum
separation between the objects on the surface of
the moon which can be just resolved is
approximately :-

Answer 1

Given :

The aperture of the telescope = 5m

The separation between the moon and the earth = 4×10⁵Km

Wavelength of the visible light = 5000A°

To Find :

The minimum separation between the objects on the moon = ?

Solution :

• we know the formula  

             $\theta = 1.22\frac{\lambda}{d}\rightarrow Equation(1)$

• Also we have the relation

             $\theta = \frac{d}{D} \rightarrow Equation(2)$

• By comparing both the equations,2e get the distance of separation

             $\frac{d}{D} =1.2\times \frac{\lambda}{d}$

             $\frac{d}{4\times 10^{8}} =1.2\times \frac{5500\times 10^{-10}}{5}$

             $d=53.68m$

The minimum separation between the objects on the moon is 53.68m.