A lens used as a simple magnifier gives magnification of 6. What is its focal length?

28 How is the terrestrial telescope different from the astronomical telescope? 29 How will you distinguish between a compound microscope and a telescope. 31 A compound microscope has an objective of focal length 1.0 cm and an eyepiece of focal length 4.0 cm. If the length of the tube is 20 cm, find the magnification of the compound microscope. 32 A telescope has an objective of focal length 140.0 cm and an eyepiece of focal length 5.0 cm. Find
(i) the magnification of the telescope for viewing distant objects for normal adjustment
(ii) separation between the objective lens and the eyepiece.