2. Questions Bank
  3. 10th Class
  4. Science
  5. Light - Reflection and Refraction

10th Class Science Light - Reflection and Refraction Question Bank Light

  • question_answer
    Two lenses of power \[+\text{12 D}\]and \[-2D\] are put in contact. What is their equivalent focal length?

    A)  10 cm                    

    B)         \[\text{12}\text{.5 cm}\]

    C) \[\text{16}\text{.6 cm}\]             

    D)         \[\text{8}\text{.33 cm}\]

    Correct Answer: A

    Solution :

                    \[P={{P}_{1}}+{{P}_{2}}\]                    \[=+12-2=+10\,\,D\] \[\therefore \]  \[f=\frac{1}{P}=0\cdot 1m=10\,\,cm\]


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