Optics Question 93

Question: The object distance u, the image distance v and the magnification m in a lens follow certain linear relations. These are

[Roorkee 2000]

Options:

A) $ \frac{1}{u}\text{ versus }\frac{1}{v} $

B) m versus u

C) u versus v

D) m versus v

Show Answer

Answer:

Correct Answer: A

Solution:

For a lens $ \frac{1}{f}=\frac{1}{v}-\frac{1}{u} $

$ \Rightarrow \frac{1}{v}=\frac{1}{u}+\frac{1}{f} $ …..(i)

Also $ m=\frac{f-v}{f}=1-\frac{v}{f} $

$ \Rightarrow m=( -\frac{1}{f} )\ v+1 $ ….(ii)

On comparing equations (i) and (ii) with $ y=mx+c. $

It is clear that relationship between $ \frac{1}{v} $ vs $ \frac{1}{u} $ and m vs v is linear.



NCERT Chapter Video Solution

Dual Pane