Light Behavior in Different Mediums

The lecture covers the concept of refraction and Snell's Law, explaining how light bends when it enters a new medium. It introduces Fermat's Principle, which states that light travels the path that takes the least time. Snell's Law is detailed, showing the relationship between angles and velocities in different mediums. The index of refraction is explained as the ratio of light's velocity in a vacuum to that in a medium. Example problems illustrate Snell's Law, and the behavior of light in various mediums is discussed, including changes in velocity, wavelength, and frequency. Reflection principles are also covered.

What happens to light when it enters a new medium?

• It speeds up.

• It changes color.

• It stops.

• It bends.

According to Fermat's Principle, how does light travel between two points?

• Along the longest path.

• Along the path that takes the least time.

• In a straight line.

• In a circular path.

In the lifeguard thought experiment, why is it faster to spend more time on the beach?

• Because the beach is shorter.

• Because running is faster than swimming.

• Because the water is deeper.

• Because the person is closer to the beach.

What does Snell's Law relate to in terms of light traveling through different mediums?

• The temperature of the medium.

• The color of light.

• The speed of light in a vacuum.

• The angles of incidence and refraction.

What is the index of refraction?

• The wavelength of light.

• The angle of refraction.

• The ratio of the speed of light in a vacuum to the speed in a medium.

• The speed of light in a vacuum.

When light moves from water to glass, what happens to its angle relative to the normal?

• It bends away from the normal.

• It bends toward the normal.

• It remains unchanged.

• It becomes perpendicular.

What remains constant when a wave enters a new medium?

• Velocity

• Wavelength

• Frequency

• Amplitude

What happens to the wavelength of light when it moves from a higher to a lower index of refraction?

• It increases.

• It decreases.

• It stays the same.

• It becomes zero.

What is the rule for the angle of reflection?

• It is twice the angle of incidence.

• It is half the angle of incidence.

• It equals the angle of incidence.

• It is unrelated to the angle of incidence.

Why can the index of refraction never be less than one?

• Because light cannot travel faster than in a vacuum.

• Because it is always greater than the speed of sound.

• Because it is a constant value.

• Because it depends on the temperature.