Question 423Electricity & Electronics - QMED

The correct answer is D) using a storage battery or battery charger to 'flash' the field. The loss of residual magnetism in an alternator or generator can be corrected by "flashing the field" using a storage battery or battery charger. This process restores the magnetic field in the rotor, allowing the generator to build up voltage and resume normal operation. The other options are incorrect because: A) running the generator at normal speed with the field rheostat fully counter-clockwise would not restore the magnetic field; B) allowing the generator to run at 10% of normal speed for 5 minutes is an ineffective method; and C) running the rotor in the opposite direction for 5 minutes would not properly restore the magnetism.