1. When moonlight strikes the surface of a calm lake, what happens to this light?
(a) All of it reflects from the water surface back to the air.
(b) Some of it reflects back to the air; some enters the water.
(c) All of it enters the water.
(d) All of it disappears via absorption by water molecules.
2. If you shine a light through an optical fiber, why does it come out the end but not out the sides?
(a) It does come out the sides, but this effect is not obvious because the sides are so much longer than the ends.
(b) The sides are mirrored, so the light reflects.
(c) Total internal reflection makes the light reflect from the sides.
(d) The light flows along the length of the fiber, never touching the sides.