Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • (a) A person suffering from myopia (near-sightedness) was advised to wear corrective lens of power . A spherical lens of same focal length was taken in the

(a) A person suffering from myopia (near-sightedness) was advised to wear corrective lens of power -2.5\; D. A spherical lens of same focal length was taken in the laboratory. At what distance should a student place an object from this lens so that it forms an image at a distance of 10\; cm from the lens ?

(b) Draw a ray diagram to show the position and nature of the image formed in the above case.

 

 

 

 
 
 
 
 

Answers (1)

(a)

f(m) = 1/ P(D)

f = 1/ −2.5D = −10/ 25D = −0.4m = −40cm

f=-40 cm v =-10 cm u = ?

1/ v − 1/ u = 1/ f

1/ −10 cm − 1/ u = 1/ −40 cm

1/ u = 1/ −40 + 1/ 10

= 3/40 

Hence u = -40/3 =-13.3 cm 

(b) Since the power is –ve , the lens used is concave / diverging, 

Posted by

Safeer PP

View full answer

Similar Questions

Latest Question