Question

Problem 24.07 Constants Part A Light of wavelength 700 nm falls on two slits and produces an interference pattern in which the third-order bright red fringe is 36 mm from the central fringe on a screen 3.0 m away. What is the separation of the two slts? Express your answer to two significant figures and Include the appropriate units d Value Units Submit Regue Answer Provide Feedback

Answer 1

answer) the formula for constructive interference is given by

dsin$\Theta$=m$\lambda$, where m=0,1,2,3..........

for nth fringe the formula is

nth fringe=m$\lambda$L/d

so for the third fringe

36*10^-3m=3*700*10^-9m*3/d

d=3*700*10^-9m*3/36*10^-3m=0.175mm

so the answer is 0.18 mm or 1.8*10^-4m or 180$\mu$m