What is kaleidoscope$?$ State the principle on which it is based.

In which direction will a light ray falling along the normal to a mirror be reflected$?$

(Choose one from$:$ No reflection $/$ Retraces its path)

A boy is standing at a distance of $4 \mathrm{m}$ in front of a mirror. He moves $2 \mathrm{m}$ towards the mirror. In which direction will the image move$?$

(Choose one from$:$ Towards the mirror $/$ Away from the mirror)

In the figure shown below, $\mathrm{MN}$ is a plane mirror. $\mathrm{W}, \mathrm{X}, \mathrm{Y}$ and $\mathrm{Z}$ are four children. Mark the positions of the reflections of $\mathrm{W},\hspace{0.17em}\mathrm{X}, \mathrm{Y}$ and $\mathrm{Z}$ in the mirror. Answer the following questions.

a. Which child/children can see their own images in the mirror$?$

b. Can child $\mathrm{W}$ see the images of $\mathrm{X}, \mathrm{Y}$ and $\mathrm{Z}$ in the mirror$?$