This preview shows page 1. Sign up to view the full content.
Unformatted text preview: er and marking where the
rays exit the lens and where the reach the edge of the paper. Then remove the lens and trace back the rays
using a meter stick.
How does the focal length you measured compare with that of the plano-convex lens of the same
curvature? Note and record the appropriate information on your worksheet.
Once again, use Equation 5 to ﬁnd an expected focal length and compare to the measured value. 9 10 Sign Conventions for the Lens Maker’s Equation
R 1* R 2* Focal length
(nm = Air = 1) Type of lens + − f>0
(focusing) Bi-convex − − f > 0 or f < 0
(Depends on R1, R2) Meniscus + + f < 0 or f > 0
(Depends on R1, R2) Meniscus ∞ − f>0
(focusing) Plano-convex + ∞ f>0
(focusing) Plano-convex ∞ + f<0
(defocusing) Plano-concave − ∞ f<0
(defocusing) Plano-concave − + f<0
View Full Document
- Spring '14