JEE Mains · Physics · STD 12 - Ray optics and optical instruments
- JEE Mains 2021
- Hard
- Numerical
A prism of refractive index \(n_{1}\) and another prism of refractive index \(n_{2}\) are stuck together (as shown in the figure). \(n_{1}\) and \(n_{2}\) depend on \(\lambda\), the wavelength of light, according to the relation \({n}_{1}=1.2+\frac{10.8 \times 10^{-14}}{\lambda^{2}} \text { and } {n}_{2}=1.45+\frac{1.8 \times 10^{-14}}{\lambda^{2}}\) The wavelength for which rays incident at any angle on the interface \(B C\) pass through without bending at that interface will be \(....\,nm.\)

Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(600\)
Step-by-step Solution
Detailed explanation
For no deviation, \(n_{1}=n_{2}\)
\(1.2+\frac{10.8 \times 10^{-14}}{\lambda^{2}} =1.45+\frac{1.8 \times 10^{-14}}{\lambda^{2}}\)
\(0.25 =\frac{9 \times 10^{-14}}{\lambda^{2}}\)
\(\lambda^{2} =\frac{9 \times 10^{-14}}{0.25}\)
\(\lambda =\frac{3}{5} \times 10^{-6}\)
\(\lambda =6 \times 10^{-7} m\)
\(\lambda =600 nm\)
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