1: Which of the thin lenses below has the longer focal length? What is the focal length of a plane mirror?

Your TA will draw the lenses ... I couldn't get the graphics to reproduce on the html page for some unknown reason.

2: Two mirrors face each other across a square room. An infinite series of reflections can be seen. What are these reflections in terms of images? Why to the ones that seem further away also seem dimmer?

3: Two thin lenses with a focal length of magnitude 10.0 cm, the first converging and the second diverging, are placed 8.0 cm apart. An object 2.00 mm tall is placed 18.0 cm to the left of the first (converging) lens. A) How far from this first lens is the final image formed? B) Is the final image real or virtual? C) Is the final image erect or inverted? What is the height of the image?

4: When a converging lens is immersed in water, does its focal length increase or decrease in comparison with the value in air? Explain and make a drawing showing how the angles of the rays at the interfaces vary in the two cases.

5: An object is placed 16.0 cm from a screen. A) At what two points between object and screen may a converging lens with a 3.50-cm focal length be placed to obtain an image on the screen? B) What is the magnification of the image for each position of the lens?

6: If you have normal vision, you can't see clearly underwater without a mask or goggles. Why is this? Why can you see clearly with a mask or goggles? Instead of goggles, could you just wear eyeglasses? If so, should the lenses of the eyeglasses be converging or diverging?

7: Where is the near point of an eye for which a contact lens with a power of +2.75 diopter is prescribed? Where is the far point of an eye for which a contact lens with a power of -0.830 diopter is prescribed for distant vision?

8: Your grandma comes to your laboratory to visit one day. You show her a sample of the bacterium you are studying under a powerful optical microscope. She asks how the microscope makes the little object look so large. What would you tell her?

9: The focal length of the eyepiece of a certain microscope is 2.50 cm. The focal length of the objective is 16.0 mm. The distance between objective and eyepiece is 22.6 cm. The final image formed by the eyepiece is at infinity. Treat all lenses as thin. a) What is the distance from the objective to the object being viewed? B) What is the magnitude of the linear magnification produced by the objective? C) What is the overall magnification of the microscope?