A baby cow is called a calf. Adult male cows are called bulls. Adult female cows are called heifers until they give birth; after they have given birth, they are called cows.
As long as there is a fuel supply of natural gas or propane, a well-maintained backup generator will keep running. If the Generac generator is running on propane, with a 500-gallon tank, it should run 24 hours a day for over a week. How loud are they? Generac generators are very quiet.
Electrical generators found in power plants use water turbines, combustion engines, windmills, or other sources of mechanical energy to spin wire coils in strong magnetic fields, inducing an electric potential in the coils. A generator that provides alternating current power is called an alternator.