Question 19M.1A.SL.TZ2.16
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.SL.TZ2.16 |
| Level | SL | Paper | 1A | Time zone | TZ2 |
| Command term | Question number | 16 | Adapted from | N/A |
Monochromatic light travelling upwards in glass is incident on a boundary with air. The path of the refracted light is shown.
A layer of liquid is then placed on the glass without changing the angle of incidence on the glass. The refractive index of the glass is greater than the refractive index of the liquid and the refractive index of the liquid is greater than that of air.
What is the path of the refracted light when the liquid is placed on the glass?
[1]
D
A low discrimination index with most candidates choosing C. They have deduced, correctly, that the ray moves away from the normal on entering the denser medium but have apparently forgotten that the stem of the question has shown them that it reaches the glass-air boundary at an angle greater than the critical angle.
