$A$ thin prism of glass is placed in air and water successively. If $_a\mu _g = 3/2$ and $_a\mu _w = 4/3$,then the ratio of the deviation produced by the prism for a small angle of incidence when placed in air and water is

$A$ prism $(\mu = 1.5)$ has a refracting angle of $30^\circ$. The deviation of a monochromatic ray incident normally on one of its surfaces will be $(\sin 48^\circ 36' = 0.75)$.

An isosceles glass prism $\left( \mu = \frac{3}{2} \right)$ has one of its equal faces coated with silver. $A$ ray is normally incident on the other face and is reflected twice and then emerges through the base of the prism perpendicular to it,as shown in the figure. Find the angle $\theta$ of the prism in degrees. (in $^{\circ}$)

The respective angles of the flint and crown glass prisms are $A'$ and $A$. They are to be used for dispersion without deviation. The ratio of their angles $A'/A$ will be:

$A$ deviation of $5^o$ is observed from a prism whose angle is small and whose refractive index is $1.5$. The angle of the prism is.......$^o$

One face of a glass prism is silver-polished. $A$ light ray falls at an angle of $45^{\circ}$ on the other face. After refraction, it is subsequently reflected from the silvered face and then retraces its path. The refracting angle of the prism is $30^{\circ}$. The refractive index of the prism is: