Q1: An imaginary number is one that exists only in the mind of the mathematician.

ANS:B - False

An imaginary number that when squared gives a negative result ie i(iota). Imaginary numbers do exist. Despite their name, they are not really imaginary at all.

The name dates back to when they were first introduced, before their existence was really understood. At that point in time, people were imagining what it would be like to have a number system that contained square roots of negative numbers, hence the name "imaginary".