Which of the following is $NOT$ an example of a secondary voltaic cell?

Explain: Electrochemistry is a wide and interdisciplinary subject.

Which of the following statements is correct regarding the cathode of an electrochemical cell?

Assertion: The cell potential of a mercury cell is $1.35 \ V$,which remains constant.
Reason: In a mercury cell,the electrolyte is a paste of $KOH$ and $ZnO$.

The reaction $\frac{1}{2} H_{2(g)} + AgCl_{(s)} \rightarrow H^+_{(aq)} + Cl^-_{(aq)} + Ag_{(s)}$ occurs in which of the following galvanic cells?

If less than $1.1 \ V$ external opposite current is passed through the Daniell cell,for such condition answer the following questions :
$(1)$ Which are anode and cathode ?
$(2)$ Give direction for electron and current flow.