How does plane diffraction grating forms a spectrum?, Other Engineering

Assignment Help:

Q. With necessary theory explain the formation of spectrum by a plane transmission grating when composite light falls on it

OR

How does plane diffraction grating forms a spectrum? On which factors does the width of a spectral line depends?

When a beam of light of wavelength falls normally on a grating the principle maxima are formed in the direction given by

From equation (1) it is clear, that for a given order n, the angle of diffraction '?' varies with l.  As the wavelength increases, the angle of diffraction also increases.

Hence if white light is incident on grating, then each order will contain principle maxima of different wavelength in different direction. The principle maxima of all wavelength corresponding to will form the first order spectrum and so on.

The principle of maxima of all wavelength corresponding to will however be along the same direction. Hence, the zero order maxima will be white having on either side of it first order spectrum, second order spectrum and so on. Most of light is concentrated in the zero order principle maxima and the intensity goes on gradually decreasing as we move towards higher order spectrum. As we know the secondary maxima are not necessary to be seen.

The factor on which the width of spectral line depends : The angular width is inversely proportional to the total number of lines ruled on the grating and order of principal maxima and directly proportional to ?n. since the increase in ?n is less than the increase in n, therefore the angular width of principle maxima decreases for higher values of n.

 


Related Discussions:- How does plane diffraction grating forms a spectrum?

Evacuation of a high rise building - means of escape, Evacuation of a high ...

Evacuation of a high rise building - means of escape: Evacuation of a high rise building is likely to be split into two or more phases.  Initially, when the alarm activates (f

Duct with flow control-aircraft maintenance, Duct With Flow Control-Aircraf...

Duct With Flow Control-Aircraft maintenance: BERNOULLI'S THEOREM This theorem can be related to the relationship between pressure and velocity existing in the air flowing

Function ismember - set operations, function ismember - set operations: ...

function ismember - set operations: The function ismember receives two vectors as input arguments, and returns a logical vector which is of similar length as the first argumen

Survey, What''s the principles of surveying?

What''s the principles of surveying?

Probability, Suggest an example of a decision from your own experience whic...

Suggest an example of a decision from your own experience which you feel is best treated as a decision without probabilities. What principle of choice would seem appropriate?

Aviation legislation - aircraft weighing, AIRCRAFT WEIGHING NOTE:     T...

AIRCRAFT WEIGHING NOTE:     The C.A.A. will consider applications from aircraft constructors and operators to weigh certain types of aircraft on a sampling basis. (i.e. repre

thermodynamics, Steam enters in the turbine at 6 MPa and 450 deg C and exp...

Steam enters in the turbine at 6 MPa and 450 deg C and expands at some intermediate pressure 60 % of steam is extracted and remainder expands to 10 kPa at this Investigate the effe

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd