[" The "xz" plane is the boundary "],[" between two transparent medium."],[" Medium - I with "y>=0" has "],[" refractive index "mu" and medium - II "],[" with "y<=0" has a refractive index 1."],[" A ray of light in medium-I,given by "],[" vector "vec n=hat i-sqrt(3)hat j" is incident on "],[" the plane of separation.If the "],[" reflected and refracted rays make "],[" an angle of "90^(@)" with each other,"],[" then the value of "mu" is "sqrt(k)" .Find the "],[" value of "k" ."]