OCR paper questionWatch
This question is about superposition of electromagnetic waves.
Could someone please explain how to go about question 8)c)iii). of this paper: http://www.ocr.org.uk/Images/131308-...nd-photons.pdf
I know its only a 1 marker, so should be easy but I cant quite understand how in the mark scheme they just 'know' that lambda/4 is equal to 7.5mm.
I understand that the incident microwave superimposes with the reflecting wave to give maxima and minima, but without a distance between the transmitter and reflecting sheet I cant work out a path difference in order to find their phase difference.
You are forming a standing wave. The question talks about the distance between a maximum (an antinode) and a minimum (node) being 7.5mm. You should know that from drawing a standing wave the distance between a node and an antinode is 1/4 of a wavelength.