Wave Optics

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Do we have to learn the derivation of conditions for constructive and destructive interference? And in the syllabus it is mentioned that we should learn measurement of fringe width using a telescope, i need some notes for this as it's not given in our text book, and what should we learn in fresnel's biprism?

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We have to do the derivation for constructive and destructive interference. You only need to know the basic working of Fresnel's Bi-prism. You need not go into details. Do learn the diagram. I'm sorry but even I don't have notes on the measurement of fringe width using a telescope. May I know which text book you are using?

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Hey ppl... sorry to going slightly off topic but this year from wave optics Michelson's method and derivation of refraction of light(using hygens principle) are very important....

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@ Aarthi: I'm using a book published by S.Chand ,and written by P.Vivekanandan and D.K.Banarjee. But in the syllabus it's given:"mathematical deductions of interference from the equations of two progressive waves with a phase difference is not to be done",and it's given that only the conditions for constructive and destructive interference are required.

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@Saif: Thanks a lot! It was nice of you to send that.
@Abishek: I checked the syllabus. You can skip the derivation of the conditions of constructive and destructive interference. But justv remember the final formula.
For constructive interference :
phase difference=2m(pi) [m=0,1,2,3.....]
For destructive interference:
phase difference=(2m-1)(pi) [m=0,1,2,3.....]

I'll go check in my school library if i can find notes on "Measurement of fringe width using a telescope". I'll try posting it by tomorrow evening.

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@Abishek: Sorry for the delay. I am not sure if this is what we need to learn. But this is all I could find. I have searched all the books in my library and also on the net.

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Hey guys...I'm using Nootan Physics and my book also doesn't have that telescope thing....I wonder if they're talking of a spectrometer to measure fringe width...as it also uses a telescope....

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@Aarthi: thanks for that....but we need the telescope method to find the fringe width (beta)...we don't need the resolving power....plz post if you get any more info on the topic...ty Smile

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Guys, my teacher said Fresnel Biprism isn't important. and Michelson's method is not even in the syllabus. for fringe width derivation u can use any method u r comfortable with...

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Trust me I searched all I could! I couldn't find anything! Sad

And since none of the ISC text books have it I don't think that should be so important. I use Nootan too. And Michelson's method is not in syllabus. That's right Geethu. And Fresnel's Biprism we must know what it is. Don't skip it. We need not learn in detail but an overview of it.

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michelson's method is in syllabus........

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yes it is in the syllabus and anyway it's easy so it's better to learn... Smile

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ya its very much easy.....................

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Ok.. can anyone pls give a link or any source for Fresnel's Biprism? My teachers didn't do it and i hav no idea what it is..! Pls help me..

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hey geethu, you can learn the theory from this place: www.phy.iitkgp.ernet.in/1styr/12-fresnel-biprism.pdf Smile

you should download this first- it's pdf.