Given, the focal length of the objective lens is f0=1.25cm The focal length of the eyepiece is fe=5cm The separation between the objective and eyepiece is L=7.5cm The distance of this image from the objective lens is ‌v0=L−fe ‌v0=7.5cm−5cm=2.5cm The lens formula for the objective lens ‌
1
f0
‌=‌
1
v0
−‌
1
u0
‌
1
u0
‌=‌
1
2.5cm
−‌
1
1.25cm
u0‌=−2.5cm The magnification of the objective lens is M0=−‌
v0
u0
=‌
−2.5cm
−2.5cm
=1 The magnification of the eyepiece when the final image is at infinity is Me=‌