If the angle of a prism is $60^{\circ}$ and the angle of minimum deviation is $40^{\circ}$,then the angle of refraction will be (in $^{\circ}$)

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......$^\circ$

The angle of a prism is $A$. One of its refracting surfaces is silvered. Light rays falling at an angle of incidence $2A$ on the first surface return back through the same path after suffering reflection at the silvered surface. The refractive index $\mu$ of the prism is:

For a thin symmetric prism made of glass (refractive index $1.5$), the ratio of the angle of incidence to the angle of minimum deviation is . . . . . . .

For a thin prism,if the angle of prism is $4^{\circ}$ and the refractive index is $1.6$,then the angle of minimum deviation will be . . . . . . . (in $^{\circ}$)

$A$ ray of light passing through an equilateral prism has a velocity of $2.12 \times 10^8 \text{ m/s}$ in the prism material. The minimum angle of deviation is . . . . . . degrees.