Question 20N.1A.HL.TZ0.29
| Date | November 2020 | Marks available | [Maximum mark: 1] | Reference code | 20N.1A.HL.TZ0.29 |
| Level | HL | Paper | 1A | Time zone | TZ0 |
| Command term | Question number | 29 | Adapted from | N/A |
White light is incident normally on separate diffraction gratings X and Y. Y has a greater number of lines per metre than X. Three statements about differences between X and Y are
I. adjacent slits in the gratings are further apart for X than for Y
II. the angle between red and blue light in a spectral order is greater in X than in Y
III. the total number of visible orders is greater for X than for Y.
Which statements are correct?
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
[1]
B
Many candidates chose incorrect options. They need to be aware that there will usually be questions of this style and they need to practice them. The pattern of the answers is always the same and the best strategy is to try to identify a wrong answer which will then help to eliminate incorrect combinations.