Real world optical systems, such as telescopes, use a combination of multiple le

Question

Real world optical systems, such as telescopes, use a combination of multiple lenses within their system. In the case of a two-lens system as shown on the next page, the image of the object generated by the first lens (L1) becomes the object for the second lens (L2).

a) The lenses are identical with a power of 6.67 D. What is the focal length?

b) Where will the first image be located relative to L1?

c) What is the magnification of this image?

d) Where will the second image be located relative to L2?

e) What is the magnification of the second image due to L2?

f) What is the total magnification of this optical system?

g) Construct a ray diagram for the two-lens system on the next page.

Explanation / Answer

Part A)

The focal length is the inverse of the Dioptic Power

f = 1/D = 1/6.67

f = .150 m or 15 cm

Part B)

Apply 1/f = 1/p + 1/q

1/15 = 1/40 + 1/q

q = 24 cm behind L1

Part C)

M = -q/p

M = -24/40 = -.60 (Negative means inverted)

Part D)

The object distance is 30 - 24 = 6 cm

1/15 = 1/6 + 1/q

q = -10 cm (Meaning 10 cm in front of L2)

Part E)

M = -q/p = -(-10)/6

M = 1.67

Part F)

M = 1.67(-.6)

M = -1 (Again, negative means inverted)

Related Questions

Navigate

• Browse (All)
• Browse R
• Subjects

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