Concept:The only difference between an AC generator and a DC generator is the type of rings used to collect current from the rotating coil.
Explanation:An AC generator uses slip rings. These maintain a continuous connection and allow the current to reverse direction each half cycle.
This produces alternating current.
A DC generator uses split rings, also called a commutator.
The split rings reverse the connection to the external circuit every half cycle.
This converts the naturally produced alternating current into direct current.
Therefore, to change the accidental AC generator into a DC generator, the slip rings must be replaced with split rings.
Answer:D. the slip rings should be replaced with split rings