An astronomical refractive telescope has an objective of focal length 20 m and an eyepiece of focal length 2 cm. Then
A. the magnification is 1000
B. the length of the telescope tube is 20.02 m
C. the image formed of inverted
D. all of these
Answer:D
An astronomical refractive telescope has an objective of focal length 20 m and an eyepiece of focal length 2 cm. Then
A. the magnification is 1000 B. the length of the telescope tube is 20.02 m C. the image formed of inverted D. all of these