Recent content by Michael Marchenko

I can exclude B because B shows maxima, but I do not know how to exclude A and D. These are the equations for the diffraction grating and the double-slit experiment: dSin(A) = nL DL = ax It seems that this problem is about the combination of both. C is probably the correct answer...

Can there be a beat in question 30? https://en.wikipedia.org/wiki/Beat_(acoustics)

For the constructive interference the phase difference must be multiple of 360 degrees. For destructive interference the phase difference must be odd number of 180 degrees.

Doppler effect may be important here because it may have qualitative effect because the relative speed is unknown. I do not know how to post equations here.

Doppler effect may be important here. I still do not understand what are the correct answers to these questions and why.

How do I take into account the motion of the source or the receiver?

I cannot copy the questions separately. Sorry. I am trying. May be I will do that later.

I want to ask about question 27 in Cambridge university physics paper 9702/01 of October/November 2008 https://physics18.weebly.com/uploads/5/9/8/5/59854633/9702_w08_qp_01.pdfand question 30 in Cambridge university physics paper 9702/12 of May/June 2012...