Question

To best be able to determine if a distant star is really a double star, one should

a) Use a larger aperture telescope and focus on the blue part of the spectrum of light from the star

b) Use a larger aperture telescope and focus on the red part of the spectrum of light from the star

c) Use a smaller aperture telescope and focus on the blue part of the spectrum of light from the star

d) Use a smaller aperture telescope and focus on the red part of the spectrum of light from the star

Answer 1

Answer : (d) Use a smaller aperture telescope and focus on the red part of the spectrum of light from the star.

Because, The light gathering power and resolving power of the Telescope, depend only on the size of the telescope (called the aperture). The light gathering power depends on the area of the main element (the objective), while the resolving power depends on the diameter.

And, angular resolution is directly proportional to the wavelength of light and inversely proportional to the diameter of the telescope.