Practicality

Imaginary numbers are used everyday and most don't know it. Electricity and circuits are run by imaginary numbers. Everybody uses imaginary numbers when they use electricity, but the people who understand it the most are electricians. In AC (alternating current), the electricity produced is represented through positive and negative imaginary numbers and an electricians job is to balance them out. So basically, electricity runs by the balance of positive and negative imaginary numbers.