A. there is only one lens B. the objective lens have a shorter focal length than the eyepiece which is convex C. the objective lens has a longer focal length than the eyepiece which is convex D. the objective lens has a shorter focal length than the eyepiece which is concave E. the objective and the eyepiece are both convex and have the same focal length
Correct Answer: B
Explanation
  A compound microscope consists of two convex lenses: an objective lens O of small aperture and an eye piece E of large aperture. The lens which is placed towards the object is called objective lens, while the lens which is towards our eye is called eye piece. These two convex lenses i.e. the objective and the eye piece have short focal length and are fitted at the free ends of two sliding tubes at a suitable distance from each other. Although the focal length of both the objective lens and eye piece is short, but the focal length of the objective lens O is a little shorter than that of the eye piece E.
