Doubt from Wave optics

[Viraj]

Qn 24 A part .. I feel distance between slit and screen Shud have been mentioned

[Unik-Wadhwani]

I feel distance between slit and screen Shud have been mentioned

No. The question is correct.
Think a bit more and u will get your answer.

[Viraj]

Ohh is it. Fine then . Lemme see.

Then I feel this is a different profile of questions then @Unik-Wadhwani right?? Coz usually we have to see the range of sin/cos function and we get values of n...

Maybe here we Shud do sth else.. ?
Shud we think in terms of angular fringe width??

[Viraj]

@Azimuddin_Sheikh @Unik-Wadhwani @Naman @Anindya_Sikdar

[Unik-Wadhwani]

Then I feel this is a different profile of questions then @Unik-Wadhwani right?? Coz usually we have to see the range of sin/cos function and we get values of n...

A bit different i would say..

Hint : when u did the approximations of sine function
U assumed that d>> \lambda
But in this can its not that.

So shall i tell u? @Viraj

[Viraj]

Yeah I didn't use that approximation .. but for calculating I was requiring D too..

Hmm .. ok . Coz I might not have done that till now .. so better if you introduce @Unik-Wadhwani

[Unik-Wadhwani]

Path difference at - infty = -4lambda
Path difference at +infty = 4 lambda

Path difference b/w the two sources at any point on screen will lie in (-4lambda,4lambda)

So no. Of maximas = 7
When path difference = -3l ,-2l ..3l

[Viraj]

Pls tell What does I stand for in 3I ?? @Unik-Wadhwani
Ans given is 8

[Unik-Wadhwani]

L is lambda..
And sorry i read the question properly now..we need to find no. Of minima

So -7l/2 ,-5l/2,-3l/2,-l/2,l/2,3l/2,5l/2,7l/2 will be the required path difference.

Note that the max path difference can be 4l and min path difference can be -4l( at +infty and -infty respectively)

[Viraj]

Yeah i had Understood that you had mis read the question but due to the 2hr time limit cudnt edit the post ..

Thanks . @Unik-Wadhwani