<p dir="ltr"><img src="https://d2vlcm61l7u1fs.cloudfront.net/media%2F572%2F5723d965-fcb6-4ce5-94cc-dfbc5b750ff8%2Fimage" alt="Student Physics II, 2nd test, Spring 2018 1. What minimum path length difference is needed to cause a phase shift of /2 in light of wavelength 550