Question 244 of 295
A thin prism with angle made of glass having refractive index 1.54 , is combined with another thin prism made of glass having refractive index 1.72 to get dispersion without deviation. The angle of the prism in degrees is
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Answer: (A) 3
For dispersion without deviation,
$\begin{aligned}
& \left(\mu_1-1\right) A_1=\left(\mu_2-1\right) A_2 \\
& \Rightarrow \quad(1.54-1) 4^{\circ}=(1.72-1) A_2 \\
& \text { Or } A_2=\frac{0.54}{0.72} \times 4=3^{\circ}
\end{aligned}$
$\begin{aligned}
& \left(\mu_1-1\right) A_1=\left(\mu_2-1\right) A_2 \\
& \Rightarrow \quad(1.54-1) 4^{\circ}=(1.72-1) A_2 \\
& \text { Or } A_2=\frac{0.54}{0.72} \times 4=3^{\circ}
\end{aligned}$
