Physics 2-Exam 4 terms

Object place further than twice the focal length (converging lens)

Real image is inverted and smaller than the object

Object is placed between first focal length and second focal length (converging lens)

Real image is inverted and larger than the object

Object is placed between focal length 1 and the lens (converging lens)

Virtual image is upright and larger than the object

Diverging Lens

always forms an upright, virtual, smaller image on the same side as the object

positive focal length

converging lens

negative focal length

diverging lens

Distance of object is positive

object is in front of lens

Distance of object is negative 

object is behind the lens

Distance of image is positive

if an image is formed on the opposite side of the lens as the object (real image)

Distance of image is negative

image is formed on the same side of the lens as the object (virtual image)

m is positive

upright image

m is negative

inverted image

When ray of light goes from a medium with a lower index of refraction to one with a higher index of refraction:

The refracted ray bends toward the normal

When ray of light goes from a medium with a higher index of refraction to a lower index of refraction:

The refracted ray bends away from the normal

Greater the change in index of refraction

greater the change in direction of the ray

When light travels through a material with a smaller refractive index towards a material with a larger refractive index

reflection at the boundary occurs along with a phase change

When light travels from a larger towards a smaller refractive index

no phase change occurs

If neither or both of the reflected wavers have a half-cycle phase shift

constructive reflection: 2t=ml

destructive reflection: 2t= (m+1/2)l

If only one of the reflected waves has a half-cycle phase shift

constructive reflection: 2t=(m+1/2)l

destructive reflection: 2t=ml

Diffraction

After passing through an opening, waves travel in directions other than the direction of the original wave. The bending of a wave as it goes through a narrow opening.

Decrease width of opening

Increase extent of diffraction

Nearsighted

Light rays converge too early, eye too long

Farsightedness

Light rays converge too late, behind the retina, is too long