Question 18M.3.SL.TZ2.9
| Date | May 2018 | Marks available | [Maximum mark: 5] | Reference code | 18M.3.SL.TZ2.9 |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Distinguish, Identify, State | Question number | 9 | Adapted from | N/A |
The diagram represents a simple optical astronomical reflecting telescope with the path of some light rays shown.
Identify, with the letter X, the position of the focus of the primary mirror.
[1]
where the extensions of the reflected rays from the primary mirror would meet, with construction lines
eg:
[1 mark]
This arrangement using the secondary mirror is said to increase the focal length of the primary mirror. State why this is an advantage.
[1]
greater magnification
[1 mark]
Distinguish between this mounting and the Newtonian mounting.
[2]
Newtonian mount has
plane/not curved «secondary» mirror
«secondary» mirror at angle/45° to axis
eyepiece at side/at 90° to axis
mount shown is Cassegrain
OWTTE
Accept these marking points in diagram form
[2 marks]
A radio telescope also has a primary mirror. Identify one difference in the way radiation from this primary mirror is detected.
[1]
waves collected above mirror/dish
waves collected at the focus of the mirror/dish
waves detected by radio receiver/antenna
waves converted to electrical signals
[1 mark]