Lens and Mirror problems

1. Compare and contrast convex and concave lenses.

2. Compare and contrast convex and concave mirrors.

3. Consider a lens, f = +12cm, with an object located 20cm in front of it. Find the following:
a. type of lens
b. di
c. type of image (real or virtual)
d. magnification of image
e. whether or not image is upside-down or right-side up
f. Where could you place object so that you get NO image?
g. Where could you place object so that you only get virtual images?

4. Repeat question 3 for a lens with f = -12cm.

5. Repeat question 3 for a mirror with f = +20cm.

6. Give a practical use for a convex lens, concave lens, convex mirror and concave mirror. (One for each.)

7. What is, in general, the effect of covering a lens or mirror in half?