What device other than a plane mirror can be used to turn a ray of light through $180°$? Draw a diagram in support of your answer.

In the given figure a ray of light $PQ$ is incident normally on the face $AB$ of an equilateral glass prism. Complete the ray diagram showing its emergence into the air after passing through the prism.

Write the angles of incidence at the faces $AB$ and $AC$ of the prism.

In the given figure a ray of light $PQ$ is incident normally on the face $AB$ of an equilateral glass prism. Complete the ray diagram showing its emergence into the air after passing through the prism.

Name the phenomenon which the ray of light suffers at the face $AB$, $AC$ and $BC$ of the prism.

Two isosceles right –angled glass prisms are placed near each other as shown in the following figure. Complete the path of the light ray entering the first prism till it emerges out of the second prism.