Which of the following does not participate when the light reaction synthesizes only $ATP$ or performs the cyclic flow of electrons?

In which process is $NADP^+$ reduced to $NADPH$?

Photophosphorylation is the synthesis of ..........

The following $(I-VI)$ are the main steps of chemiosmotic $ATP$ synthesis in the light reaction. Arrange them in the correct order:
$I$. $H^+$ concentration gradient established
$II$. $H^+$ diffuses through $ATP$ synthase
$III$. Carriers use energy from electrons to move $H^+$ across the membrane
$IV$. Electrons from $PS-II$ pass along the electron transport chain
$V$. Light excites electrons in $PS-II$
$VI$. Energy of $H^+$ flow is used by $ATP$ synthase to make $ATP$

The assimilatory power produced during the light reaction in green algae is:

Which of the following is required for the synthesis of $ATP$ via photophosphorylation?