A Beam of Light,traveling in Air,strikes a Plate of Transparent

Multiple Choice

A beam of light,traveling in air,strikes a plate of transparent material at an angle of incidence of 56.0°.It is observed that the reflected and refracted beams form an angle of 90.0°.What is the index of refraction of this material?

A) 1.40
B) 1.43
C) 1.44
D) 1.48