The figure below shows a thin-lens representation of a compound microscope (not

Question

The figure below shows a thin-lens representation of a compound microscope (not to scale). The objective produces a real image I of object O just inside the focal point F1 of the eyepiece. Image I then acts as an object for the eyepiece, which produces a virtual final image I that is seen by the observer. Assume that in such a microscope the objective has focal length fob = 4.08 cm and the eyepiece has focal length fey = 7.93 cm. The distance between the lenses is 25.6 cm. (Assume a near point of 25cm.)

(a) What is the tube length s? ____cm
(b) If image I is to be just inside focal point F1', how far from the objective should the object be?_____ cm
(c) What then is the lateral magnification m of the objective? ____
(d) What then is the angular magnification m of the eyepiece?____
(e) What then is the overall magnification M of the microscope? ____

Explanation / Answer

(a)tube length=S= distance between lenses- Fe- Fob

S=25.6 - 4.08 - 7.93

S= 13.59 cm

(b) image distance= q= 13.5+ 4.08 = 17.62 cm

using mirror formula, 1/p+1/q= 1/f

1/4.08 = 1/p + 1/17.62

p = 5.31cm.

(c) m = - tube length/Fob

m=-s/Fob

m= -13.59/4.08

m= -3.33

(d) m = near point/Fe

m=25/fe

m = 25/7.93

m= 3.15

(e) M = m xm

M=(3.15)(-3.33)

M = -10.5

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.