Question

  What combination the best image the best ability to astronomers to view differentiate the stars that are very close to each other through a telescope If he can adjust the color (red, green or blue) of the light allowed into the telescope and she has a choice of three different size objective mirrors.?

Answer 1

According rayleigh criteria of resolving power. The minimum angular seperation between two points which can just be resolved by an optical instrument is given by

(Theta)min=1.22(wavelength)/(diameter of lens)

So if we decrease the wavelngth then (theta)min will decrease hense the angular seperarion between two object will decrease it means that we can see more closely placed light source distinctly if we use smaller wavelngth and also if we increases the diameter of the aperture.

So as among red green and blue. Blue light has the smallest wavelength so we will adjust blue light and use the teleacope with biggest aperture