Sonu consults the doctor for the need of a lens of power -4.5 D for correction of his vision. Few questions came into his mind. Answer the below questions by using the above data.
1. What could be the defect sonu is suffering from?
(i) Myopia
(ii) Hypermetropia
2. What is the focal length of the lens required for correcting distant vision?
(i) -22 cm
(ii) 0.667 m
(iii) 0.567 m
3. What is the nature of corrective lens?
(i) Positive
(ii) Negative
4. What is the formula for finding the focal length of the lens?
(i) \(\frac1{P^2}\)
(ii) \(\frac1{P}\)
(iii) P
5. What is the unit for measuring the power of the lens?
(i) Dioptre
(ii) Millimeter
