During the light reaction,electrons are transferred by the splitting of $H_2O$ through the $ETC$,which results in the reduction of:

Why does cyclic photophosphorylation occur in stroma lamellae?

The minerals involved in the photolysis of water are:
$I$ Manganese
$II$ Calcium
$III$ Magnesium
$IV$ Chloride

In photosystem $I$,the first electron acceptor is

The electrons produced by the splitting of water are received by ......

Assertion $(A) : H^+$ gradient across the thylakoid membrane is essential for the formation of $\text{ATP}$.
Reason $(R) :$ Breakdown of $H^+$ gradient due to the movement of protons through $F_0$ of $\text{ATP}$ synthase releases enough energy to activate $\text{ATP}$ synthase enzyme that catalyses the formation of $\text{ATP}$.