Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A thin prism of angle $15^{\circ}$ made of glass of refractive index $\mu_1=1.5$ is combined with another prism of glass of refractive index $\mu_2=1.75$. The combination of the prism produces dispersion without deviation. The angle of the second prism should be
PhysicsRay OpticsNEETNEET 2011 (Mains)
Options:
  • A $7^{\circ}$
  • B $10^{\circ}$
  • C $12^{\circ}$
  • D $5^{\circ}$
Solution:
1125 Upvotes Verified Answer
The correct answer is: $10^{\circ}$
For without deviation
$$
\begin{aligned}
\frac{A}{A^{\prime}} & =\frac{\mu^{\prime}-1}{\mu-1} \\
\frac{15^{\circ}}{A^{\prime}} & =\frac{1.75-1}{1.5-1} \\
\frac{15}{A^{\prime}} & =\frac{0.75}{0.50} \\
A^{\prime} & =\frac{0.50 \times 15}{0.75}=10^{\circ}
\end{aligned}
$$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.