1. The problem statement, all variables and given/known data The green line of gaseous mercury at 546nm fals on a double-slit apparatus. If the fifth dark fringe is at 0.150 degree from the centerline, what is the slit separaton? 2. Relevant equations d sin (theta) = m* lambda 3. The attempt at a solution ok i used the above equatiob to find the d, slit separation as d=m*lambda/sin(theta) but im getting the wrong answer....and im not able to figure out the problem....plez som1 help.....!!