11. When you use a self-focusing camera, the photoelectric effect occurs when
a. light combines with the earth’s magnetic field.
b. light energy is converted into electrical current that
adjusts the opening in the lens.
c. light entering the lens is converted to an image on the film.
d. X-ray photons are used to produce a picture.
e. light energy is reflected by a material it strikes.
12. Which of the following does not determine the physical properties of materials?
a. material strength
b. the arrangement of atoms in the material
c. the bonding type
d. the shape of the material
e. All of the above affect physical properties.
13. Which material would have the strongest compressive strength?
a. egg shell
b. a ream of paper
c. pile of dry sand
d. rope
e. shopping bag
14. A superconductor can be described as having
a. electrons that are bound to individual atoms.
b. electrons that are free to move individually around the
material, colliding with atoms from time to time.
c. only a few electrons that are free to move around the material.
d. electrons that come together to form pairs.
e. electrons that are bound together so tightly they do not move.
15. If you start a current flowing in a superconducting wire that is kept cold, and then remove the power source, the result would be
a. the current would stop flowing immediately.
b. the current would continue to flow forever.
c. the current would flow through the superconductng wire for
about twice as long as it would have through copper wire.
d. electrons would move through the wire, losing a great deal of energy.
e. the superconducting wire would not be able to generate a
magnetic field.
