AP Physics 2 Refraction and Diffraction
Concave Lens
Thick on the edge and thin in the middle. It is a diverging lens so it will only produce: virtual, upright, smaller images.
Convex Lens
Thin on the edges and thick in the middle. It is a converging lens so it can produce 6 different types of images.
Thin Lens Equation
(1/f)=(1/p)+(1/q)
Magnification of Lens
-q/p but it can also be calculated with (image height (h'))/(object height(h))
Spectrometer
A device that separates light into its monochromatic components.
Compound Microscope
A device that uses two different lenses to magnify an object much more than a single lens can.
Index of Refraction
A measurement of the speed of light in a transparent material.
Mirage
A phenomenon produced by refraction in the atmosphere. The bending light rays can be seen on a hot day when there is a large difference between the temp directly above the pavement and a couple of feet over.
Diffraction Grating
A piece of glass or metal that has a lot of parallel slits in it so when you shine a light (typically a laser) through the holes it crates interference fringes on the screen
Positive and Negative Lenses
A positive lenses refers to a convex lens while a negative lens refers to a convex lens. The positive and negative represent the focal point for different lenses
Interference Fringes
A series of dark and bright bands produced by light interference
Diffraction
A wave phenomena when waves bend as they are passed through a narrow slit (it works best when the slit is about the size of the wave length).
Critical Angle
At some angle of incidence the wave will reflect and not refract. To find the critical angle use smells law and set the angle of refraction to 90.
Chromatic Aberration
Different colors have different wavelengths and refract at different angles so different colors are focused at different points.
Laser
Instruments that are able to produce a narrow beam of coherent, monochromatic light.
Snells Law
How to calculate the angle of refraction
Reversibility of Light Rays
Light rays are reversible
Monochromatic
Light that has a single wave length, monochromatic light is needed in order for interference to occur.
Resolving Power
The ability of an optical instrument to separate closely adjacent images.
Angle of Incidence
The angle of the incoming ray measured from the normal line.
Angle of Refraction
The angle that is formed by the ray once it enters the new medium. It is ALWAYS measured with respect to the normal line.
Dispersion
The process of separating polychromatic light into its component wave lengths.
Cornea; Retina
The transparent front of the eye that acts like a converging lens, focusing light on the retina. The retina acts as a screen on which the cornea focuses light.
Total Internal Reflection
When a wave goes from a slower medium (high index of refraction) to a fast medium (low index of refraction) and does not refract, but instead reflects.
Myopia
When the cornea converges the image too much and the image is focused in front of the eye. It is commonly known as nearsightedness and near objects are blurry while close objects are distorted. It is corrected using a diverging lens.
Hyperopia
When the cornea doesn't converge the image enough and the image is in focus behind the retina. This is known as farsighted where distant objects are clear, but nearby objects are blurry and distorted. This is corrected using a converging lens.
Constructive interference
When two light rays combine to form an amplitude that is greater than original
Destructive Interference
When two light rays of the same wave length combine to form an amplitude that is less than it was originally
Coherent Light
When two waves are within a whole integer multiple of the wavelength and have the same frequency
Equations for Interference
check pg 529
Refraction
the bending of light when it enters a new medium.
Incoherent light
the opposite of coherent
