– The focal length of each lens of Ramsdens’s eyepiece is 4 cm. Then the equivalent focal length of the eye-piece will be
A. 3 cm
B. 5 cm
C. 7 cm
D. 9 cm
Answer:A
– The focal length of each lens of Ramsdens’s eyepiece is 4 cm. Then the equivalent focal length of the eye-piece will be
A. 3 cm B. 5 cm C. 7 cm D. 9 cm