Which of the following statements is true about the voltaic cell?

Which of the following statements is $NOT$ correct?

Which of the following statements regarding a mercury battery is $NOT$ true?

Assertion : If $\lambda^o_{Na^{+}}$ and $\lambda^o_{Cl^{-}}$ are molar limiting conductivity of sodium and chloride ions respectively,then the limiting molar conductivity for sodium chloride is given by the equation :
$\Lambda^o_{NaCl} = \lambda^o_{Na^{+}} + \lambda^o_{Cl^{-}}$
Reason : This is according to Kohlrausch law of independent migration of ions.

Which of the following formulae is used to obtain the value of $E_{\text{cell}}^{\circ}$ for a reaction taking place in a Dry cell?

Provide basic information on batteries.