In a Michelson interferometer, in order to shift the pattern by half a fringe, one of the mirrors at the end of an arm must be moved by: A) one wavelength
B) half a wavelength
C) one-quarter wavelength

Aprotein molecule in an electrophoresis gel has a negative charge. the exact charge depends on the ph of the solution, but 30 excess electrons is typical. what is the magnitude of the electric force on a protein with this charge in a 1600n/c electric field? write in two significant numbers, and also in newton