A unit vector along the incident ray of light is i. The unit vector for the corresponding refracted ray of light is r . n, a unit vector normal to the boundary of the medium and directed towards the incident medium. A unit vector along the incident ray of light is i. The unit vector for the corresponding refracted ray of light is r . n a unit vector normal to the boundary of the medium and directed towards the incident medium. September 17, 2020 Category: Uncategorised (JEE Advanced Physics by BM Sharma + GMP Solutions) , Facebook Messenger WhatsApp Share this:TwitterFacebook Related