Question

When \[i=i_c\], what is the angle of refraction?

Options

• \[r=0^\circ\]

• \[r=i\]

• \[r=90^\circ\]

• \[r=i_c\]

Answer 1

At the critical angle, the angle of refraction is \[90^\circ\]. The refracted ray then grazes along the surface.