Why does matter obtain electric charge?

$(a)$ $A$ comb run through one's dry hair attracts small bits of paper. Why? What happens if the hair is wet or if it is a rainy day? (Remember,a paper does not conduct electricity.)
$(b)$ Ordinary rubber is an insulator. But special rubber tyres of aircraft are made slightly conducting. Why is this necessary?
$(c)$ Vehicles carrying inflammable materials usually have metallic ropes touching the ground during motion. Why?
$(d)$ $A$ bird perches on a bare high power line,and nothing happens to the bird. $A$ man standing on the ground touches the same line and gets a fatal shock. Why?

When a glass rod is rubbed with a silk cloth,charges appear on both. $A$ similar phenomenon is observed with many other pairs of bodies. Explain how this observation is consistent with the law of conservation of charge.

The minimum charge on an object is

Which of the following properties is $NOT$ satisfied by a static electric charge?

An insulating solid metal sphere is charged with a charge $+Q$. The distribution of $+Q$ charge on the surface will be .......