Date | November 2020 | Marks available | 4 | Reference code | 20N.3.SL.TZ0.12 |
Level | Standard level | Paper | Paper 3 | Time zone | 0 - no time zone |
Command term | Sketch | Question number | 12 | Adapted from | N/A |
Question
Outline the meaning of normal adjustment for a compound microscope.
Sketch a ray diagram to find the position of the images for both lenses in the compound microscope at normal adjustment. The object is at O and the focal lengths of the objective and eyepiece lenses are shown.
Markscheme
the final image lies at the near point «often assumed to be » ✓
any 2 correct rays from O for objective lens ✓
forming an intermediate image at approximate position shown
OR
use of image from objective lens as object for eyepiece lens ✓
any 2 correct rays for eyepiece lens from intermediate image ✓
ray extension to form a final image ✓
Allow ECF for MP2, MP3 & MP4 for badly drawn rays.
MP4 allow final image to be off the page