REFLECTION AND REFRACTION

Question 1

When a mirror reflects sunlight, one has to protect the eyes to avoid the
blinding glare. The sun’s incident rays are almost parallel; they are almost
parallel when reflected. This kind of reflection is called ________.

Polished surface like mirrors and bright metals produce ________, and the resulting images are sharply defined.

Answer 1

• Regular Reflection

Question 2

If the rays of an incident beam of light happen to fall on an irregular surface,
the normal drawn to the surface will not be parallel and the reflected light
will __________ in all directions.

Answer 2

Disperse

Question 3

The dispersal of a reflected light is called ___________. __________ would seem useless to use because we do not get any clear images, yet the diffusion of light is of great importance.

Answer 3

Diffusion, Diffused Light

Question 4

• Light travels fastest in a vacuum where its velocity is _____________.
• In other substances (minerals) the velocity of light is ___________.

Answer 4

• 3 x 10^8 m/s
• > 3 x 10^8 m/s

Question 5

The ratio of the velocity of light in a vacuum to the velocity of light in another medium is called the _________ of the medium.

Answer 5

• refractive index

Question 6

• Refractive indices are
  always __________
• Refractive indices for minerals are typically __________.

Answer 6

• greater than one
• between 1.4 and 2.0

Question 7

• When a ray of light passes from one medium to another, the propagation
  direction generally changes. This process, called __________, is the principle behind lenses and may be used to explain many common observations from ___________ to internal reflection in prisms.
• The degree of refraction or bending
  depends on the relative refractive indices of the two mediums according to a relationship called __________.

Answer 7

• Refraction, “bent oars”
• Snell’s Law

Question 8

The rays do not enter the air at all but instead point along the surface of the medium with the higher index of refraction. If the angle were increased, then no refracted ray would exist, resulting in _____________.

Answer 8

• total internal reflection

Question 9

If it were possible to look at a beam of light from one end, we would probably see some of the waves vibrating
sideways, others up and down, and still others at various angles as seen in figure a. not all crystals transmit light
perfectly. Some types like tourmaline, transmit light waves which vibrate in only one direction or phase shown in figure b. light passing through this type of material is said to be
_______

Answer 9

• Polarized