The path of a refracted ray of light in a prism is parallel to the base of the prism only when the

Consider an equilateral prism (refractive index $ \sqrt{2} $). $A$ ray of light is incident on its one surface at a certain angle $ i $. If the emergent ray is found to graze along the other surface,then the angle of refraction at the incident surface is close to . . . . . . . (in $^{\circ}$)

$A$ ray is incident at an angle of incidence $i$ on one surface of a small angle prism (with angle of prism $A$) and emerges normally from the opposite surface. If the refractive index of the material of the prism is $\mu$,then the angle of incidence is nearly equal to

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:

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 . . . . . . .

The graph between the angle of deviation $(\delta)$ and the angle of incidence $(i)$ for a prism is: