The above process in which $\mathrm{\alpha }$ and $\mathrm{\beta }$ form remain in equilibrium with acyclic form and a change in optical rotation is observed. What is the rotation called?

The true/false statements about the following compounds are:

${\mathrm{S}}_1:$ This carbohydrate polymer is composed of $\mathrm{\beta }-\mathrm{D}(+)$ glucose.
${\mathrm{S}}_2:$ It has $\mathrm{\alpha }-(1,4)$ glycosidic linkage.
${\mathrm{S}}_3:$ It is a non-reducing carbohydrate.