1. Light (em radiation) of wavelength 2 microns is
A] gamma ray
B] x-ray
C] visible
D] infrared
E] microwave

2. Light (em radiation) of wavelength 2 cm is
A] ultraviolet
B] visible
C] infrared
D] microwave
E] radiowave

3. When a beam of light enters a piece of plexiglass, what will be its path? (np > 1)

4. The wave equation is time-reversal symmetric.
A laser in air shines a beam of light that hits a diver, rightmost path.
The diver has a laser pointer, and wants to hit the air laser. What direction should he point it?
Or choose D: no direction will work.

5. Enter the following numbers on the scantron, to one sig fig, in the format a1 x 10a2
1&2: 19
3&4: e8
5&6:
7&8: x 102