The residual magnetism of a self excited DC generator is lost. To build up its emf what to be done to regain the residual magnetism?
- A. The field winding must be excited by double the rated DC voltage
- B. The armature connection must be reversed
- C. The field winding connection must be reversed
- D. Field winding must be excited by low voltage DC supply
Answer: D. Field winding must be excited by low voltage DC supply
Explanation: When residual magnetism is lost, 'field flashing' is performed by temporarily exciting the field winding with a low-voltage external DC supply (such as a battery) to restore residual flux.