Optics Flashcards UNIT TEST! TUESDAY!!

Ch 11.1 - What is light Ch 11.2 - How is light produced? Ch 11.4 - Ray Model of Light Ch 11.6 - Laws of Reflection Ch 11.7 - Images in Plane Mirrors Ch 11.9 - Images in Curved Mirrors

electromagnetic spectrum

radio waves

microwaves

infrared light

visible light

ultraviolet light

X rays

gamma rays

What’s are some uses for radio waves?

• AM/FM radio

• TV signals

• cellphone communication

• radar

• astronomy (for example, discovery of pulsars)

What’s are some uses for microwaves?

• telecommunications

• microwave ovens

• astronomy (for example, background radiation associated

with the Big Bang)

What’s are some uses for infrared light?

• remote controls (for example, DVD players and

game controllers)

• lasers

• heat detection (for example, leakage from windows, roofs)

and remote sensing

• keeps food warm (in fast-food restaurants)

• astronomy (for example, discovering the chemical

composition of celestial bodies)

• physical therapy

What’s are some uses for visible light?

• human vision

• theatre/concert lighting

• rainbows

• visible lasers

• astronomy (for example, optical telescopes, discovering

the chemical composition of celestial bodies)

What’s are some uses for ultraviolet light?

• causes skin to tan and sunburn

• increases risk of developing skin cancer

• stimulates production of vitamin D

• kills bacteria in food and water (sterilization)

• “black” lights

• ultraviolet lasers

• astronomy (for example, discovering the chemical

composition of celestial bodies)

What are some uses for X-rays

• medical imaging (for example, of teeth and broken bones)

• security equipment (for example, scanning of luggage at

airports)

• cancer treatment

• astronomy (for example, study of binary star systems,

black holes, the centres of galaxies)

What are some uses for gamma rays

• cancer treatment

• astronomy (for example, study of nuclear processes

in the universe)

• product of some nuclear decay

Light from Incandescence

The production of light as a result of high temperature

Light from Electric Discharge

The process of producing light by passing an electric current through a gas

Light from Phosphorescence

The process of producing light by the absorption of UV light results in the emission of visible light over extended periods of time

Light from Fluorescence

The absorption of ultraviolet light, causing visible light to be emitted immediately

Light from Chemiluminescence

Chemiluminescence is the direct production of light as the result of a chemical reaction with little or no heat produced

Light from Bioluminescence

Bioluminescence is the production of light in living organisms as the result of a chemical reaction with little or no heat produced

Light from Triboluminescence

Triboluminescence is the production of light from friction as a result of scratching, crushing, or rubbing certain crystals

Light from a Light-Emitting Diode (LED)

A light-emitting diode (LED) is a light produced as a result of an electric current flowing in semiconductors

Semiconductor

A material that allows an electric current to flow only in 1 direction

LAWS OF REFLECTION?

1. The angle of incidence equals the angle of reflection.

2. The incident ray, the reflected ray, and the normal all lie in the same plane.

Specular Reflection?

Diffuse Reflection?

Specular Reflection: reflection of light off a flat smooth surface

Diffuse Reflection: reflection of light off a rough surface

Lower density to higher density = what happens to the speed of light?

The speed of light decreases

Higher density to lower density = what happens to the speed of light?

The speed of light increases

What is a Critical Angle?

When the angle of incidence results to an angle of refraction of 90 degrees.

What is total internal reflection

When the angle of incidence is greater than the critical angle (90 degrees angle of refraction)

What is apparent depth

what the depth of an object that “appears” to be due to the refraction of light in a transparent medium

What is a Mirage

Formed by refractions and the total internal reflection caused by the earth’s atmosphere. (Ex: When the road appears to look like it has a pool of water)

What is Shimmering

When light gets refracted as it passes through different temperatures

What is Dispersion

When a ray of light splits of into its constituent colors

How does Dispersion work?

Each colour of visible light travels at a different speed of light when it goes through a glass prism

How is a rainbow formed

You can only see a rainbow when the Sun is behind you.

1. Refraction: Light enters a raindrop, causing dispersion from water to air.

2. Partial Internal Reflection: occurs when this light hits the back of the raindrop.

3. Refraction: Light exits the raindrop, going from water to air.

This is the light the human eye sees, which we perceive as a rainbow. Your brain projects these light rays backwards and forms a virtual image of the spectrum: a rainbow.