Two lenses of power 3D and -ID are kept in contact. What is focal length and nature of combined lens?
A. 50 cm, convex
B. 200 cm, convex
C. 50 cm, concave
D. 200 cm, concave
Answer:A
Two lenses of power 3D and -ID are kept in contact. What is focal length and nature of combined lens?
A. 50 cm, convex B. 200 cm, convex C. 50 cm, concave D. 200 cm, concave