Question

Analyse the following observation table showing variation of image distance (v) with
object distance (u) in case of a convex lens and answer the questions that follow, without doing
any calculations,

Object distance.image.distanc
(u) cm. (v)cm
-90. 18
-60. 20
-30. 30
-20. 60
-18. 90
-10. 100

a) What is the focal length of the convex lens? Give reason in support of your answer.
b) Write the serial number of that observation which is not correct. How did you arrive at
this conclusion?
c) Take an appropriate scale to draw ray diagram for the observation at serial No.4 and find
the approximate value of magnification.​

Answer 1

Explanation:

variation of image distance (v) with

object distance (u) in case of a convex lens and answer the questions that follow, without doing

any calculations,

Object distance.image.distanc

(