Homework Help: micole

Posted by PHYSICS on Sunday, August 19, 2007 at 8:00pm.

White light strikes a diffraction grating (930 lines/mm) at normal incidence. What is the longest wavelength that forms a second-order maximum?
I used the equation [(1/d)sin(90)]/m = wavelength: [(1/0.93m)(1)] /2 = 0.5376m. To convert to nm I multiplied by 10^-9. This is incorrect. Can anyone help? Thanks

Isn't d the reciprocal of 930/mm? or

or 1/d= .001m/930=1.08E-8 m or .108nm?

check my thinking. In your equation, unit wise, if you are to have length on the right, you have to have length units on the left.

I remember the grading equation as

d sinTheta /n= lambda, where d is in meters.
Perhaps that is your error.

micole - Jonathon, Friday, December 17, 2010 at 6:03pm
The answer should follow such that
Lines/mm --> d --> (1/930mm)/1000mm/m
d = 1.075e-6 meters
set sin theta = 90o = (1)
(dsin(Theta))m=mlambda
(1.075e-6 (1))/2)= 5.375e-7 or 537nm.

Answer this Question

Related Questions

physics - An 11-mm wide diffraction grating has rulings of 550 lines per mm. ...
physics - An 11-mm wide diffraction grating has rulings of 550 lines per mm. ...
physics - A diffraction grating gives a second-order maximum at as angle of 31&#...
physics - A diffraction grating gives a second-order maximum at as angle of 31&#...
PHYSICS - 1) A diffraction grating with 2.500 x 10^3 lines/cm is used to examine...
Physics - Diffraction grating #1 has half the lines/cm that diffraction grating...
Physics - Light of wavelength 600 nm illuminates a diffraction grating. The ...
physics - Why is white light separated into a spectrum of colors when it is ...
Physics - Visible light is incident perpendicularly on a diffraction grating of ...
Physics - The light shining on a diffraction grating has a wavelength of 470 nm...

For Further Reading

First Name:
School Subject:
Answer: