2. Questions Bank
  3. JEE Main & Advanced
  4. Physics
  5. Ray Optics

JEE Main & Advanced Physics Ray Optics Question Bank Refraction at Curved Surface

  • question_answer
    A magnifying glass is to be used at the fixed object distance of 1 inch. If it is to produce an erect image magnified 5 times its focal length should be                                            [MP PMT 1990]

    A)            0.2 inch                                   

    B)            0.8 inch  

    C)            1.25 inch                                

    D)            5 inch

    Correct Answer: C

    Solution :

               \[m=\frac{v}{u}=5\Rightarrow v=5\] inch (Given u = 1 inch)                    Using sign convention \[u=-\ 1\ inch,\ \ v=-\ 5\ inch\]            \[\therefore \frac{1}{f}=\frac{1}{v}-\frac{1}{u}=\frac{1}{-5}-\frac{1}{-1}\Rightarrow f=1.25\ inch\]


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