Review Flashcards
What is light?
Light is a fast moving energy wave consisted of electric and magnetic waves
What is the speed of light in a vacuum?
3.00 x 10^8 m/s
How does light travel?
In a straight line
What is a medium
A medium is a physical substance that can transfer energy.
water, air, glass
What is frequency?
The number of wavelengths per unit of time (Hz)
What is a wavelength
The distance between one waves crest and another
What is the electromagnetic spectrum?
It measures the frequency, energy, and wavelength of the types of electromagnetic waves
Radio waves —> gamma rays
What is the order of the electromagnetic spectrum
Long to short wavelengths
Radio Long Microwave Infrared Visible Ultraviolet X-ray Gamma. Short
What is the order of the electromagnetic spectrum
Highest to lowest frequency
Gamma. High X-ray Ultraviolet Visible Infrared Microwave Radio. Low
What is a use of radio waves
Cell phone, radio, tv
What is a use of microwave rays
Microwave ovens
Some uses for infrared waves
Remote controls, lasers
Uses of visible light
Human sight, rainbows
Ultraviolet uses
Skin tanning, black lights, skin cancer risk
X-ray uses
Cancer treatment, medical imaging
Gamma rays uses
Cancer treatment
What are the two sources of light?
Luminous- creates its own light
Non luminous- does not create its own light
What are the types of light?
Incandescence Electric discharge Phosphorescence fluorescence Chemiluminescence Bioluminescence LED Laser
What does L.A.S.E.R. stand for?
Light amplification by stimulated emissions of radiation
What’s the first law of reflexion?
The angle of incidence is equal to the angle of reflection
What is the 2nd law of reflection
The incidence, reflected, and normal all lie on the same plane
What are the two types of reflections?
Specular- smooth surface like a mirror
Diffuse- irregular/ dull surface
What is refraction
Refraction happens when light travels from one medium into a different one
What does SALT stand for?
Size
Attitude
Location
Type
What are the two types of curved mirrors
Concave- curved away from object
Convex- curved toward object
Rules for locating images in concave mirrors
1- rays parallel to the principal axis reflect through the focus
2- rays going through the focus will reflect parallel to the principal axis
3- rays through the centre will reflect on themselves
4- rays that hit the vertex will follow the 1st rule of reflection
What is the salt when the object is placed…
Behind C
Smaller
Inverted
Between C and F
Real
What is the salt when the object is placed…
Between C and F
Bigger
Inverted
Behind C
Real
What is the salt when the object is placed…
Inside F
Bigger
Upright
Behind mirror
Virtual
What is the salt when the object is placed…
On C
Same size
Inverted
At C
Real
What is the salt when the object is placed…
On F
No clear image
What are the rule of convex mirror reflections
1- Ray parallel to principal axis will reflect as if it came from F
2- Ray aimed towards F will reflect parallel to principal axis
3- Ray aimed at C will reflect on itself
What is the salt of an object in a convex mirror
Smaller
Upright
Behind mirror
Virtual
Rules of refraction
1- incidence, normal, and refracted Ray are all in the same plane
2- when speed decreases, light will bend toward the normal
3- when speed increases, light will bend away from the normal
What is an index of refraction
Amount by which a medium decreases the speed of light
It has no units
Air has the lowest index 1.00 while water is 1.33
How do you find the index of refraction
N= C
_________
V
C is the speed of light in air
N is the speed of light in any medium
What is total internal reflection
If the angle of incidence is greater than the critical angle, then there will be a reflection instead of a refraction
How do rainbows work
Rays of light refract as they enter water droplets which causes dispersions (the different colours) water refracts again once it can leave and forms the rainbow we know
How do mirages work
Temperature can change the index of refraction of air. if the ground ins hotter than the sky, a gradient is created and when light is refracted it created a virtual image
What are the rules for images in converging lenses
1- Ray parallel to principal axis will refract through the focus
2- Ray goes through F and refracts parallel to principal axis
3- Ray goes straight through optical centre
What is the salt of an image in a converging image if….
It is beyond 2F’
Smaller
Inverted
Between 2F and F
Real
What is the salt of an image in a converging image if….
It is at 2F’
Same size
Inverted
At 2F
Real
What is the salt of an image in a converging image if….
Between 2F’ and F
Bigger
Inverted
Beyond 2F
Real
What is the salt of an image in a converging image if….
At F’
No clear image
What is the salt of an image in a converging image if….
Inside F’
Bigger
Upright
Beyond 2F’
Virtual
Rules for locating an image in a diverging lens
1- Ray parallel to principal axis is refracted as if it came from F
2- Ray that is aimed at F’ refracted parallel to principal axis
3- Ray that goes through optical centre will continue
What is the only salt of any image in a diverging lens
Smaller
Upright
Same side as object
Virtual
