11. Light (3rd exam)

Light is an ___ wave, consisting of ___ ___ and ___ fields ___ to each other and the direction of ___.

electromagnetic, oscillating electric and magnetic, perpendicular, propagation

What is wave-particle duality?

Light exhibits both wave and particle properties

What’s the speed of light in a vacuum?

c = 3.00 × 10⁸ m/s

The EM spectrum includes all types of electromagnetic radiation, classified by ___ or ___.

wavelength (λ) or frequency (f)

All EM waves travel at the same speed in a vacuum but differ in ___ and ___.

energy and wavelength

The speed of light is related to its ___ and ___ by the wave equation:

wavelength and frequency, c= (wavelength)(frequency)

What’s the law of reflection?

Angle of incidence = Angle of reflection

What are the two types of reflection?

specular and diffuse reflection

What’s specular reflection?

Occurs on smooth surfaces like mirrors, light reflects in a single direction, produces clear images

What’s diffuse reflection?

Occurs on rough surfaces like paper or walls, light scatters in many directions, no clear image formed, but objects are still visible.

What happens to images in flat mirrors?

Flat mirrors create virtual, upright, and inverted images. The image appears the same distance behind the mirror as the object is in front. No actual light passes through the image, it only looks to be coming from there.

What happens to images in a curved mirror?

Concave mirrors (curved inward) can form different kinds of images depending on object distance. Convex mirrors (curved outward) always produce smaller, upright images. Applications include telescopes, headlights, and security mirrors.

What’s refraction?

The bending of light as it passes from one medium to another due to a change in speed.

When entering an optically dense medium,

Light slows down and bends toward the normal (an imaginary line perpendicular to the surface)

When leaving an optically dense medium,

Light speeds up and bends away from the normal

When does total internal reflection (TIR) occur?

Occurs when light attempts to pass from a more dense medium to a less dense one at a large enough angle, and all light is reflected internally rather than refracted. (Only happens slow to fast NOT fast to slow!)

The amount of energy a light wave carries depends on its ___. High frequency light carries ___, while a low frequency light carries ___.

frequency, more, less

What’s linear propagation?

Light travels in a straight line until something happens to change its direction (reflection or refraction).

What is reflection?

light being bounced off something

What’s an incident wave?

the incoming light wave

What’s a reflected wave?

The wave that is bounced away from the surface

What is the normal?

to a flat surface is a vector that is perpendicular to that surface.

What’s the critical angle?

The angle of incidence above which total internal reflection occurs

How does a prism work when a white light is shined into the prism but different colors come out?

Different colors change speed by different amounts so they bend at different angles so refraction can separate colors.

What are mirages?

Caused by layers of air at different temperatures. Hot air near the ground is less dense,

bending light rays upward, creating the illusion of water.