Answer the following questions:
(d) Why must both the objective and the eyepiece of a compound microscope have short focal lengths?

Explanation

The angular magnification of eye-piece is
`((25)/(f_e) + 1)` . If `f_e` is smaller then angular magnification increases.
`rArr` Also, magnifcation of objective is
`(v_0)/(|u_0|) = (1)/((|u_0|//f_0)-1)` where `f_0` is less than `|u_0|`, then it is large . To observe the very nearer objects, microscope is use. Hence, `|u_0|` is small but `f_0` is smaller.