If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting. Calculate the focal length of objective.
A. 100 cm
B. 10 cm
C. 20 cm
D. 25 cm
Answer:A
If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting. Calculate the focal length of objective.
A. 100 cm B. 10 cm C. 20 cm D. 25 cm