DC generators are _______ excited.

• A. externally excited
• B. independently excited
• C. promptly excited
• D. self excited

Answer: (D)

DC generators use self-excitation: the field current is supplied from the generator’s own output rather than from an outside power source. The process starts with residual magnetism in the magnetic poles, which produces a small output voltage. This voltage drives current into the field winding through the regulator, strengthening the magnetic field and increasing the generated EMF until a steady output voltage is reached. External or independently excited systems rely on a separate power source to energize the field, which is not how these units are normally configured. Promptly excited isn’t a standard term for this context.