Why does the conductivity increases in presence of strong electrolytes and decreases in presence of weak electrolytes?

Match the following:

Define the term: Corrosion
Write two applications of electrochernical series.

Assertion: Galvanised iron does not rust.

Reason: Zinc has a more negative electrode potential than iron.

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

Identify the following changes as Physical or Chemical.

Rusting of iron.