Question

‘A’ and ‘B’ consult an eye doctor with vision defects. The doctor gave them to wear - 1.5 D

and 2 D spectacles.

Write answer from above information

i) Write the types of the vision defects of ‘A’ and ‘B’

ii) What type of lens should they wear ?

iii) What is the unit for lens power ?

iv) Find the focal length value to - 1.5 D lens ?​

Answer 1

Answer:

1) A - Myopia

  B - Hypermetropia

2) A - Concave lens

   B - Convex lens

3) Lens power unit - Dioptre

4)  P = 1/f

    -1.5 = 1/f

     -1.5f = 1

          f = 1/-1.5

          f = -0.67m or -67cm

Therefore focal length of concave lens (-1.5D) = -0.67m or                       -67cm

Hope this helps!

MARK AS BRAINLIEST!!

Answer 2

( i ). A has myopia and B has hypermetropia.

( ii ). A should wear concave lens and B should wear convex lens.

( iii ). Unit of power of lens is 'dioptre' (D)

( iv ). Power = 1/f (m)

f (cm) = 100/ P = 100/1.5 = - 66.7 m or - 0.67 cm