When installing an emergency back-up generator with an output of 22 kW, single-phase, 120/240-volts for a farm house, the ampacity of phase conductors from the generator terminals to the first overcurrent protective device shall not be less than ____ of the nameplate current rating of the generator where the design of the generator does not prevent overloading.

Most states require an electrician to pass an exam to receive a journeyman or master electrician license.  State exams cover these topics:  Electrical Theory, Trade Knowledge, Grounding and Bonding, Wiring Methods and Installation, Overcurrent Protection, Load Calculations, etc.