Question

UdlS.
13. A student conducted an experiment with a biconvex lens
and prepared the following table.
60
50
30
15.2
Object distance (u) 70
in cm
Image distance (v) 14.5
in cm
Focal length (f) 12.01
in cm
16.2
I 17
20
12.12
12 13
11.92 120
Answer the following questions based on the information
given in the above table.
i) What is the reason you think for different values of focal
length in the above table?
ii) How do you decide the focal length of the above lens?
What is its value?​

Answer 1

Answer:

1). the different value of focal length because of object distance was changing

2). the focal length decide like when image form virtual image at that point called focal