In a Telescope, compared to the eyepiece lens the objective lens has

In a refracting telescope, the objective lens is designed to collect as much light as possible from distant astronomical objects. To achieve high light-gathering power and better resolution, the objective lens must have a larger aperture (diameter) compared to the eyepiece. Additionally, the magnification of a telescope is determined by the ratio of the focal length of the objective lens to the focal length of the eyepiece lens (M = F/f). To achieve significant magnification, the objective lens is designed with a much larger focal length, while the eyepiece has a shorter focal length. Therefore, the objective lens possesses both a larger focal length and a larger aperture than the eyepiece to ensure a bright, magnified, and clear image of distant objects.