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

Copper displaces which of the following metals from their salt solutions?

On the basis of position in the electrochemical series,the metal which does not displace hydrogen from water and acid is

The following limiting molar conductivities are given as:
$\lambda_{m(H_{2}SO_{4})}^{0} = x \ S \ cm^{2} mol^{-1}$
$\lambda_{m(K_{2}SO_{4})}^{0} = y \ S \ cm^{2} mol^{-1}$
$\lambda_{m(CH_{3}COOK)}^{0} = z \ S \ cm^{2} mol^{-1}$
The $\lambda_{m}^{0} \ (\text{in } S \ cm^{2} mol^{-1})$ for $CH_{3}COOH$ will be:

Standard electrode potentials of $Zn$ and $Fe$ are known to be $(i) -0.76 \ V$ and $(ii) -0.44 \ V$ respectively. How does this explain that galvanization prevents rusting of iron while zinc slowly dissolves away?

Which cell differs from the fundamental principle point of view?