Question

Here are some questions to complete after you have determined the wavelength with a diffraction grating. (A laser was used)

equation used: n x lambda=d x sintheta

Question:

What effect will the following have on the pattern produced? Explain your reasoning:

1.increasing distance to screen, D

2.changing from red light to green light

3.rotating the diffraction grating through ninety degrees

4.using a point source of white light


please help with all the parts of this question im really confused but below are amy attempts;

1. Increasing the distance would mean all other values increase?
2.green wave has a shorter wavelength so id get a lower wavelength number?
3.The laser would not show the screen it was on would go blank?
4. THe values increase?

These are my closest guesses i could get please help.

Answer 1

yes, you are really confused. Nearly all these can be answered by examining the equations involved, and I get the distinct impression you have done no more than brief glancing. Thinking is required.

Answer 2

Im not sure please help, i had to put on at least something of what i had done so i was hoping for corrections?

Answer 3

I wasn't sure so i posted this

Answer 4

Well, how about just posting your thoughts on number 4.

Answer 5

For number 4 i think that red light has a shorter wavelength so the change to white would cause all the values to increase. Im not sure about anything else please help

Answer 6

Please help if you know this because i cant say something i dont know

Answer 7

White light has lots of wavelengths, like all of them.
Red light has LONGER wavelength (lower frequency and photon energy) than other colors. The high frequency end is violet.
Perhaps look at:
http://www.livephysics.com/physical-constants/optics-pc/wavelength-colors/
Look, we can not help you if you have not even read the chapter in your text book. If you do not have a text handy, Google diffraction grating.