Tutorial 3 Solutions
Jan 21 / 23, 2014
1)
ECE 318
See textbook for solutions to 5.60, 5.75, 5.77, 5.81, 5.86
5.39 These are two examples of beam expanders with magnification -f2/f1. Parallel rays entering lens 1
converge to focal point and then diverge to lens two and become collimated (parallel). For a second
lens of negative focal length, the focal points coincide on right hand side, so rays converge from 1st
lens to 2nd lens and become collimated before reaching the focus.
2)
3)
Examine Fig. 5.91b (Hecht) to see the eye accommodated to image at a distance L = Dnear away. By
straining your eye to see near, diverging rays between the magnifying lens and the eye are focused onto
the retina for an object that can now be positioned slightly closer to the lens than in the case (so = fo)
presented in class for the unaccommodated eye. The solution is Eqns. 5.75 to 5.78.
Microscope: unaccommodated Fig. 5.99 / accommodated: figure below
Telescope: unaccommodated Fig. 5.106 / accommodated: Fig. 5.105 and 5.107
http://www.tutorvista.com/content/physics/physics-ii/optical-instruments/compound-microscope.php
4) 5.65, 5.84, 5.87, 5.88