light and waves

What happens when you change factors when creating diffraction patterns

*** Relationship between colors of light, wavelength, freq, diffraction amount and band distance 

Describe the freq and wavelength of red light  (compared to other colors, consult the EM spectrum if you need to)

Because Red Light has a long_______ wavelength, when it diffracts it will spread little  /  a lot

Set up the diffraction pattern with two slits again with red light and make the slits as small as possible 

Look at the distance between the bright bands in the diffraction pattern. If red spreads little / a lot, then the bright bands should be further / closer apart. 

Let’s check this by using a blue light. (you can take a picture of the red spectrum so that you can compare them)

Blue has a ____short_______ wavelength, so when it diffracts it will spread little  /  a lot

If it spreads  little  /  a lot then the bright bands should be  further / closer apart when compared to RED. 

Summary:

Light that has a large wavelength like RED, has a small_______ frequency. 

They diffract more / less, resulting in a diffraction pattern of closer / further apart bright bands. 

Light that has a small wavelength like BLUE, has a large_______ frequency. 

They diffract more / less, resulting in a diffraction pattern of closer / further apart bright bands. 

***Changing the distance between the slits

Reset phet, change to color lights, default green color, two slits, screen, slit separation 1000nm

Observe the diffraction pattern’s distance between bright bands. 

Increase the slit separation to 1400nm or 1700nm. When the slit separation increases, the distance  between bright bands decreases________.

Decrease the slit separation to 1000nm. When the slit separation decreases, the distance  between bright bands ___increases_________

***Changing the distance of the slits from the source

Repeat, but this time varying the distance of the slits from the source of light. You can do this by dragging the double arrows on the bottom

If the slits are closer to the source, then the bands are close together / far apart 

If the slits are further from the source, then the bands are close together / far apart