Which of the following statements is true ? [1]
A. A convex lens has 4 dioptre power having a focal length 0.25 m
B. A ‘convex lens has -4 dioptre power having a focal length of 0.25 m
C. A concave lens has 4 dioptre power having a focal length 0.25 cm.
D. A concave lens has -4 dioptre power having a focal length 0.25 m.
Answer:A
Which of the following statements is true ? [1]
A. A convex lens has 4 dioptre power having a focal length 0.25 m B. A ‘convex lens has -4 dioptre power having a focal length of 0.25 m C. A concave lens has 4 dioptre power having a focal length 0.25 cm. D. A concave lens has -4 dioptre power having a focal length 0.25 m.