A boy uses spectacles of focal length -60cm. He had few doubts in his mind and consults doctor for clearing them. Answer the below questions by using the above information.
1. Name the defect of vision he is suffering from.
(i) Myopia
(ii) Hypermetropia
2. Which lens is used for correction of this defect?
(i) Concave lens
(ii) Convex lens
3. What is the power of this lens?
(i) -1.667 D
(ii) -9.667 D
(iii) -9.667 D
(iv) 10 D
4. What is the focal length of this lens?
(i) -0.60 cm
(ii) -0.60 m
(iii)-10.60 m
5. What does the negative sign of focal length indicates ?
(i) Concave lens
(ii) Convex lens
