An optical instrument uses eye lens of power 16D and objective lens of power 50D and has a tube length of 16.5 cms . Name the optical instrument and calculate its magnifying power , if it forms the final image at infinity. Share with your friends Share 7 Vijay Shankar Yadav answered this Dear Student, This is a compound microscope because in compound microscope eyepiece has smaller powerand magnifying power=-lDfofe here l → tube length D→least distance of clear vision fo and fe are focal length of objective and eyepiece respecitvilysomagnifying power=-.165×.251/50×1/16=-33 Regard 18 View Full Answer