![a) Determine the 'effective focal length' of the combination of the two lenses in Exercise 9.10, if they are placed 8.0 cm apart with their principal axes coincident. Does the answer depend a) Determine the 'effective focal length' of the combination of the two lenses in Exercise 9.10, if they are placed 8.0 cm apart with their principal axes coincident. Does the answer depend](https://d10lpgp6xz60nq.cloudfront.net/physics_images/U_LIK_SP_PHY_XII_C09_E01_021_S01.png)
a) Determine the 'effective focal length' of the combination of the two lenses in Exercise 9.10, if they are placed 8.0 cm apart with their principal axes coincident. Does the answer depend
![optics - How is focal length defined for a two-lens system, separated by a distance $d$? - Physics Stack Exchange optics - How is focal length defined for a two-lens system, separated by a distance $d$? - Physics Stack Exchange](https://i.stack.imgur.com/fwrwB.png)
optics - How is focal length defined for a two-lens system, separated by a distance $d$? - Physics Stack Exchange
![When two thin lenses are kept in contact prove that their combined or effective focal length F is given by 1F1F11F2 where the terms have their usual meaning When two thin lenses are kept in contact prove that their combined or effective focal length F is given by 1F1F11F2 where the terms have their usual meaning](https://content-grail-production.s3.amazonaws.com/quetsion-media/24066af9-5039-4636-b492-415c8f1e7ec2-image.png)
When two thin lenses are kept in contact prove that their combined or effective focal length F is given by 1F1F11F2 where the terms have their usual meaning
Derive an expression for equivalent focal length of two thin lenses kept in contact. - Sarthaks eConnect | Largest Online Education Community
![Physics 55.4 Optics- Multiple Lenses (3 of 12) The Double Lens: The Equivalent Focal Length - YouTube Physics 55.4 Optics- Multiple Lenses (3 of 12) The Double Lens: The Equivalent Focal Length - YouTube](https://i.ytimg.com/vi/GxemspUuOSU/mqdefault.jpg)