JEE Main & Advanced Physics Ray Optics Sample Paper Topic Test - Refraction of Light Through Curved Surfaces

  • question_answer
    A wire mesh consisting of very small squares is viewed at a distance of 8 cm through a magnifying converging lens of focal length 10 cm, kept close to the eye. The magnification produced by the lens is

    A) 5

    B) 8

    C) 10

    D) 20

    Correct Answer: A

    Solution :

    [a] \[\frac{1}{f}=\frac{1}{v}-\frac{1}{u}\] Given, f = 10 cm (as lens is-converging) \[u=-\,8\,cm\] (as object is placed on left side of the lens) Substituting these values in Eq. (i), we get \[\frac{1}{10}=\frac{1}{v}-\frac{1}{-8}\] \[\Rightarrow \]   \[\frac{1}{v}=\frac{1}{10}-\frac{1}{8}\] \[\Rightarrow \]   \[\frac{1}{v}=\frac{8-10}{10}\] \[\therefore \]      \[v=\frac{80}{-2}=-40cm\] Hence, magnification produced by the lens \[m=\frac{v}{u}=\frac{-40}{-8}=5\]

You need to login to perform this action.
You will be redirected in 3 sec spinner