# Two light rays having the same wavelength in vacuum are in phase initially. Then the first ray travel a path through a medium of refractive index , while the travel second ray travels a path of length through a medium of refractive index . The two waves are then combined to observe interference. The phase difference the two waves is a) b) c) d) ## Question ID - 150139 :- Two light rays having the same wavelength in vacuum are in phase initially. Then the first ray travel a path through a medium of refractive index , while the travel second ray travels a path of length through a medium of refractive index . The two waves are then combined to observe interference. The phase difference the two waves is a) b) c) d) 3537

 (b) Optical path for 1st ray= Optical path for 2ndray  Phase difference,  Two polaroids are placed in the path of unpolarized beam of intensity such that no light is emitted from the second polaroid.  If a third Polaroid whose polarization axis makes an angle with the polarization axis of first Polaroid, is placed between these polaroids, then the intensity of light emerging from the last Polaroid will be a) b) c) d)  