Pigments are mixed by the $......$ method to produce various colors.

Which of the following is not a primary color of light?

Which of the following colors are primary colors?

Account for the following:
$(a)$ Part of the human eye that helps in changing the focal length of the eye lens.
$(b)$ The condition resulting due to the eye lens becoming cloudy.
$(c)$ The factors on which the colour of the scattered white light depends.
$(d)$ The range of vision of a normal eye.
$(e)$ The sky appears dark to the astronauts in space.

In an astronomical telescope,how is the focal length of the objective lens compared to the focal length of the eyepiece?

What are the colors obtained by mixing primary colors called?