Aphysics instructor wants to project a spectrum of visible-light colors from 400 nm to 700 nm as part of a classroom demonstration. she shines a beam of white light through a diffraction grating that has 700 lines per mm, projecting a pattern on a screen 2.9 m behind the grating. how wide is the spectrum corresponding to m=1?

Explanation:

Given

Distance of screen from light source

we know in slit Experiment

, where =angle between the path and a line from the slits to the screen

and

where y is the position of First maxima corresponding

calculations for  

for n=1

Spectrum Width

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.