Question -
Answer -
(a)Though the image size isbigger than the object, the angular size of the image is equal to the angularsize of the object. A magnifying glass helps one see the objects placed closerthan the least distance of distinct vision (i.e., 25 cm). A closer objectcauses a larger angular size. A magnifying glass provides angularmagnification. Without magnification, the object cannot be placed closer to theeye. With magnification, the object can be placed much closer to the eye.
(b) Yes, the angularmagnification changes. When the distance between the eye and a magnifying glassis increased, the angular magnification decreases a little. This is because theangle subtended at the eye is slightly less than the angle subtended at thelens. Image distance does not have any effect on angular magnification.
(c) The focal length of aconvex lens cannot be decreased by a greater amount. This is because makinglenses having very small focal lengths is not easy. Spherical and chromaticaberrations are produced by a convex lens having a very small focal length.
(d) The angular magnificationproduced by the eyepiece of a compound microscope is 
Where,
fe = Focal length ofthe eyepiece
It can be inferred that if fe is small, thenangular magnification of the eyepiece will be large.
Theangular magnification of the objective lens of a compound microscope is givenas 
(e)When we place our eyes tooclose to the eyepiece of a compound microscope, we are unable to collect muchrefracted light. As a result, the field of view decreases substantially. Hence,the clarity of the image gets blurred.
Thebest position of the eye for viewing through a compound microscope is at theeye-ring attached to the eyepiece. The precise location of the eye depends onthe separation between the objective lens and the eyepiece.