refraction of light

Question

Light travels from a region of fused quartz into a region of ethyl alcohol, making an angle of incidence of 70 degrees. Which of the following best describes the path of the light as it moves into the ethyl alcohol?

A)The light will bend toward the normal

B) The light will bend away from the normal

C)The light will continue without bending

D)The light will move in some manner not determined by the information here.

Answer 1

Hi

If light rays incident from high dens (with higher refractive index) material to low dens material it will bend a way from the normal unless the incident angle is equal or greater than the critical angle .

We need to know sin-1 (n_r/n_i) to find the critical angle , then compare it with 70 to determine the way light ray will act .

So D is the best answer.