What Is the Focal Length of the Concave Lens in This Lens-Mirror Combination?

Click For Summary
SUMMARY

The focal length of the concave lens in the given lens-mirror combination can be determined using the lens formula 1/f = 1/v - 1/u. Given that the convex lens forms a real image at a distance of 50 cm, this image acts as the object for the concave lens, which is positioned 10 cm behind the convex lens. Since the final image coincides with the object, the effective object distance for the concave lens is -40 cm. Solving the lens equation reveals that the focal length of the concave lens is -20 cm.

PREREQUISITES
  • Understanding of lens formulas, specifically 1/f = 1/v - 1/u
  • Knowledge of real and virtual images formed by lenses
  • Familiarity with ray diagrams for optical systems
  • Basic concepts of concave and convex lenses
NEXT STEPS
  • Study the derivation of the lens formula 1/f = 1/v - 1/u
  • Explore ray diagram techniques for complex lens systems
  • Learn about the properties of concave and convex lenses in optical applications
  • Investigate the effects of multiple lens combinations on image formation
USEFUL FOR

Students in physics, optical engineers, and anyone studying lens systems and image formation in optics.

avalanche007
Messages
1
Reaction score
0

Homework Statement


a convex lens forms a real image of a point object at a distance of 50 cm from convex lens. a concave lens is placed 10 cm behind convex lens on image side. on placing a plane mirror on the image side and facing the concave lens it is observed that final image now coincides with the object itself. find focal length of concave lens.

Homework Equations


1/f = 1/v - 1/u

The Attempt at a Solution


v= +50cm for convex lens as real image is formed on opposite side to object.
this acts as object for concave lens
unable to proceed further
 
Physics news on Phys.org
Try drawing a ray diagram.
 

Similar threads

Lens Maker's Formula - Confusion in the derivation
  • · Replies 15 ·
Replies
15
Views
2K
Focal length of the eyepiece lens in a compound microscope
  • · Replies 7 ·
Replies
7
Views
2K
Analyzing this 2-lens optical system
  • · Replies 5 ·
Replies
5
Views
2K
Find the location and length of the final image
  • · Replies 2 ·
Replies
2
Views
1K
Image position in an optical system?
  • · Replies 5 ·
Replies
5
Views
2K
Mirror placed horizontally between two half convex lenses
  • · Replies 11 ·
Replies
11
Views
1K
Calculate a radius of a circle on a screen
  • · Replies 3 ·
Replies
3
Views
1K
Image Distance with two concave lenses
  • · Replies 4 ·
Replies
4
Views
4K
Calculating Chromatic Aberration
  • · Replies 2 ·
Replies
2
Views
2K
Is the Solution for Rotation of Spherical Mirrors Incorrect?
  • · Replies 16 ·
Replies
16
Views
2K