Question

In an experiment for determination of refractive index of glass of a prism by $i-\delta plot$ it was found that a ray incident at angle ${35}^{\circ }$ suffers a deviation of ${40}^{\circ }$ and that it emerges at angle ${79}^{\circ }.$ In that case which of the following is closest to the maximum possible value of the refractive index?

• A. $1.6$
• B. $1.7$
• C. $1.8$
• D. $1.5$

Answer 1

The correct option is A $1.6$

$\delta ={40}^0,i={35}^0,e={79}^0$

Since $\delta =i+e-A$, A being angle of prism.

$A={74}^0$

${\mu }_{max}=\frac{sin\left(\frac{A+\delta }{2}\right)}{sin\left(\frac{A}{2}\right)}$

Putting the values in above equation, we get ${\mu }_{max}=1.44$. Closed option is $1.5$