What does the given figure represent?

Which of the following substances undergoes sublimation?

Water rises to a height $h$ in a capillary tube. If the length of the capillary tube above the surface of water is made less than $h$,then

Let $M$ be the foot of the perpendicular from a point $P$ on the parabola $y^2=8(x-3)$ onto its directrix and let $S$ be the focus of the parabola. If $\triangle SPM$ is an equilateral triangle,then $P$ is equal to

The extent of charge of a lead accumulator is determined by

During meiosis $I$,the chromosomes start pairing at