2. Solved Papers
  3. JCECE Engineering

JCECE Engineering JCECE Engineering Solved Paper-2010

  • question_answer
    A microscope is focussed on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index \[1.5\] is placed over a mark. How should the microscope be moved to get the mark again in focus?

    A) \[1\,\,cm\]upward                         

    B) \[4.5\,\,cm\]downward

    C)  \[1\,\,cm\]downward  

    D)  \[2\,\,cm\]upward

    Correct Answer: A

    Solution :

    Apparent depth of mark as seen through a glass slab of thickness \[x\] and refractive index\[\mu \] is Apparent depth\[=\frac{\text{Real}\,\,\text{depth}}{\text{Refractive}\,\,\text{index}}\]or\[x'=\frac{x}{\mu }=\frac{3}{1.5}=2\,\,cm\] As image appears to be raised by\[1\,\,cm,\] therefore, microscope must be moved upwards by\[1\,\,cm.\]


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