Question

A students needs spectacles of power -0.50 for the correction of his
vision.
(a) Name the defect in vision the student is suffering from.
(b) Find the nature and focal length of the corrective lens.-
(c) List two causes of this defect.
Find the effective resistance between the points A and B in network shown
in figure.​

Answer 1

Lets solve for it

Explanation:

a. The defect of vision that the student is suffering from is Myopia i.e Nearsightedness. In this defect the person is able to see the near by objects clearly but the far off objects appear blur.

b.The nature of the corrective lens used is concave lens P=1/F

-0.50 = 1/F

F= 2m

c. The causes of this defect are-

  if the eyeball becomes too long.

  ciliary muscles become weak.