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 ray of light incident at an angle $\theta$ on a refracting face of a prism emerges from the other face normally. If the angle of the prism is $5^{\circ}$ and the prism is made of a material of refractive index $1.5$, the angle of incidence is
PhysicsRay Optics
Options:
  • A
    $7.5^{\circ}$
  • B
    $5^{\circ}$
  • C
    $15^{\circ}$
  • D
    $2.5^{\circ}$
Solution:
2827 Upvotes Verified Answer
The correct answer is:
$7.5^{\circ}$
As we know that the deviation
$$
\delta=(\mu-1) \mathrm{A}
$$
By geometry, the angle of refraction by first surface is $5^{\circ}$ and given $\mu=1.5$
So, $\quad \delta=(1.5-1) \times 5^{\circ}=2.5^{\circ}$ also, $\quad \delta=\theta-\mathrm{r}, \quad$.... (ii) By putting the value of $\delta$ and $r$ in equation (ii)

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.