The index of refraction of a glass rod is 1.48 at T=20C and varies linearly with temperature, with a coefficient of linear expansion of the glass of 2.5*10^-5/C. The coefficient of linear expansion of the glass is 5*10^-5/C. At 20C the length of the rod is 3 cm. A Michelson interferometer has this glass rod in one arm, and the rod is being heated so that its temperature increases at a rate of 5C/min. The light source has wavelength 589 nm, and the rod is initially at T=20C. How many fringes cross the field of view each minute?

Amnay Amimeur , 12 Years ago

Grade 12