PHY8

what are the sign conventions for objects and images for lenses?

• o: (+) object is on same side of lens as light source

  (-) image is on opposite side of lens from light source (real)

• o: (+) object is on same side of lens as light source

  (-) object is on opposite side of lens from light source (rare)

• i: (+) object is on same side of lens as light source

  (-) image is on same side of lens as light source (virtual)

• i: (+) image is on opposite side of lens from light source (real)

  (-) image is on same side of lens as light source (virtual)

when a light ray reflects from one medium to another the frequency is unaffected by refraction

• true

• false

when a light ray refracts from one medium to another how does its speed change?

• if the 2nd mediums index of refraction is lower the light ray goes faster

• if the 2nd mediums index of refraction is lower the light ray goes slower

• if the 2nd mediums index of refraction is higher the light ray goes faster

• if the 2nd mediums index of refraction is higher the light ray goes slower

what happens to the intensity of unpolarized transmitted light when it first goes through a polarizer?

• intensity is halved

• intensity is doubled

• intensity is quartered

• intensity is quadrupled

what is plane polarized light?

• light in which all the electric field vectors are lined up in one plane

• light in which all the electric field vectors are lined up in multiple planes

• light in which all the magnetic field vectors are lined up in one plane

• light in which all the magnetic field vectors are lined up in multiple planes

what is diffraction?

• the spreading out of waves as they pass through a narrow opening or around an obstacle

• the spreading out of waves as they pass through a wide opening or around an obstacle

• the condensing of waves as they pass through a narrow opening or around an obstacle

• the condensing of waves as they pass through a wide opening or around an obstacle

what is dispersion?

• when various wavelengths of light separate from one another

• when various wavelengths of light come together

• forces between molecules

• when various wavelengths of light have multiple frequencies

formula for power of a lens

• P = 1/f

  where f is focal length in meters

• P = 2/R

  where R is the radius of lens curvature

• P = 1/f

  where f is frequency

• P = R/2

  where R is the radius of lens curvature

diverging optics have

• negative focal lengths

• positive focal lengths

converging optics have

• negative focal lengths

• positive focal lengths