Chapter 26 Properties of Light
1) The natural frequency of the atoms in glass is in the
A) visible part of the spectrum.
B) ultraviolet part of the spectrum.
C) infrared part of the spectrum.
2) A solar eclipse occurs when the
A) earth passes into the moon's shadow.
B) sun passes into the earth's shadow.
C) moon passes into the earth's shadow.
3) If a light signal and a radio signal were emitted simultaneously from Alpha Centauri, the first to reach the earth would be the
A) radio signal.
B) light signal. ve-m = vlight = c = 3x108 m/s
C) both would reach earth at the same time.
4) The main difference between a radio wave and a sound wave is their different
A) basic natures.
B) wavelengths.
C) amplitudes.
D) energies.
E) frequencies.
5) Glass is opaque to wave frequencies that
A) are below its natural frequencies.
B) match its natural frequencies.
C) both of these.
D) none of these.
6) What is the wavelength of an electromagnetic wave that has a frequency of 3 kilohertz?
A) 1 km. v = f λ
B) less than 1 km. 3x108 = 3x103 λ
C) more than 1 km.
7) The moon would be at its fullest just before the time of a
A) solar eclipse.
B) lunar eclipse.
C) both of these.
D) none of these.
Chapter 28 Reflection and Refraction
8) If you walk towards a mirror at a certain speed, the relative speed between you and your image is
A) half your speed.
B) twice your speed.
C) your speed.
D) none of these.
9) A diver shines light up to the surface of a smooth pond at a 10° angle to the normal. Some light passes into the air above, and the part that reflects back into the water makes an angle to the normal of
A) 10°. Law of reflection θin = θexit
B) more than 10°.
C) less than 10°.
Part B questions: For the light leaving the water n θ ≈ n2 θ2, less then 10°
10) Your image in a plane mirror is
A) virtual.
B) real.
C) both of these.
D) neither of these.
11) Rainbows exist because light is
A) reflected.
B) refracted. (reflected causes secondary rainbows)
C) both of these.
D) neither of these.
12) When white light goes from air into water, the color that refracts the most is
A) red.
B) orange.
C) violet.
D) green.
E) all refract the same amount.
13) A primary rainbow is brighter than a secondary rainbow because
A) there is one less reflection inside the water drops.
B) the secondary bow is a dim reflection of the primary rainbow.
C) larger drops produce primary rainbows.
D) sunlight reaching it is more intense.
E) none of these.
14) If you wish to hit a blue fish with a red laser beam, you should compensate for refraction between the air and water by aiming your laser
A) below the sighted fish. Drawn on board, blue refract more than red
B) directly at the sighted fish.
C) above the sighted fish.
15) A mirage occurs for road surfaces that are
A) warm.
B) snowy.
C) wet.
D) cold.
E) hard.