(a) "If the slits in Young's double slit experiment are identical, then intensity at any point on the screen may vary between zero and four times to the intensity due to single slit". Justify the above statement through a relevant mathematical expression. (b) Draw the intensity distribution as function of phase angle when diffraction of light takes place through coherently illuminated single slit.
ANS. 11 (a) The total intensity at a point where the phase difference is ∅, is given by ? = ?ଵ + ?ଶ + 2ඥ?ଵ?ଶ ??? ∅. Here ?ଵ and ?ଶ are the intensities of two individual sources which are equal. When ∅ is 0, I = 4?ଵ. When ∅ is 90o , I = 0 Thus intensity on the screen varies between 4?ଵ and 0.
ANS. 11 (b) Intensity distribution as function of phase angle, when diffraction of light takes place through coherently illuminated single slit
