At which site of the $ATP$ synthase enzyme does $ATP$ synthesis occur?

$DCMU$ ($3$-($3$,$4$-dichlorophenyl)$-1,1-$dimethylurea) is a chemical that acts as an inhibitor of photosynthesis. What is its specific mode of action?

During $ATP$ synthesis,electrons are transported through .........

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 photochemical reaction in the chloroplast is directly associated with ...

The full expansion of $NADP$ is