Question

Snells law:
Light traveling in air strikes a glass plate at an angle theta1 = 33 (deg), where theta1 is measured
between between the incoming ray and the glass surface. Upon striking the glass, part of the beam is reflected and part is refracted. If the refracted and reflected beams make 90 (deg) with each other, what is the refractive index of the glass?

Answer 1

Reflected angle will be 33 deg

get refracted angle from

n1 sin 33 = n2 sin @,

where 2 is measured from the perpendicular extending into the glass from the interface.

Look at geometry and require @ to be 90o from 33o reflected direction

That @ will give you n2 after manipulation.