An astronomical telescope of magnifying power 8 is made using two lenses spaced 45 cm apart. The focal length of the lenses used are____________
A. F = 40 cm, f = 5 cm
B. F = 8 cm, f = 5 cm
C. F = 5 cm, f = 47 cm
D. F = 20 cm, f = 5 cm
Answer:A
An astronomical telescope of magnifying power 8 is made using two lenses spaced 45 cm apart. The focal length of the lenses used are____________
A. F = 40 cm, f = 5 cm B. F = 8 cm, f = 5 cm C. F = 5 cm, f = 47 cm D. F = 20 cm, f = 5 cm