$A$ prism of angle $A=1^{\circ}$ has a refractive index $\mu=1.5$. $A$ good estimate for the minimum angle of deviation (in degrees) is close to $N/10$. The value of $N$ is......

If the angle of minimum deviation of a prism is $30^o$,the angle of incidence is $60^o$,and the prism angle is $30^o$,then the refractive index of the prism is:

Three right-angled prisms of refractive indices $n_1$,$n_2$,and $n_3$ are fixed together using an optical glue as shown in the figure. If a ray passes through the prisms without suffering any deviation,then

When a glass prism of refracting angle $60^{\circ}$ is immersed in a liquid,its angle of minimum deviation is $30^{\circ}$. The critical angle of glass with respect to the liquid medium is (in $^{\circ}$)

$A$ prism of crown glass with a prism angle of $9^{\circ}$ and a prism of flint glass are used to make a direct vision spectroscope. If the refractive indices of crown and flint glass are $1.40$ and $1.60$ respectively,then the refracting angle of the flint glass prism will be.....$^{\circ}$

For a prism,the angle of the prism is $60^{\circ}$ and the refractive index is $\sqrt{7/3}$. The minimum possible angle of incidence so that the light ray is refracted from the second surface is (in $^{\circ}$)