The refractive index of a converging lens is $1.4$. What will be the focal length of this lens if it is placed in a medium of the same refractive index? (Assume the radii of curvature of the faces of the lens are $R_{1}$ and $R_{2}$ respectively)

  • A
    $1$
  • B
    Infinite
  • C
    $\frac{R_{1} R_{2}}{R_{1}-R_{2}}$
  • D
    Zero

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