If two 8-pole dc machines of identical armature sare wound, one with lap winding and the other with wave winding, then
A. wave-wound machine will have more rated current and more voltage
B. lap-wound machine will have more rated voltage and more current
C. lap-wound machine will have more rated voltage and less current
D. wave-wound machine will have more rated voltage and less current
Answer: D
Share your understanding of this question with the correct explanation.
The correct answer is D. The wave-wound machine will have more rated voltage and less current.
In a DC machine, the choice of winding type (lap winding or wave winding) affects the armature circuit configuration. The lap winding has multiple parallel paths in the armature circuit, while the wave winding has only two parallel paths.
When comparing two identical armature designs, one with a lap winding and the other with a wave winding, the wave-wound machine will have a higher rated voltage and a lower rated current compared to the lap-wound machine.
The wave winding allows for a higher voltage rating because each parallel path carries a fraction of the total current. This reduces the current density and allows for a higher voltage rating. However, since the current is divided among the parallel paths, the rated current is lower in the wave-wound machine.
In summary, the wave-wound machine will have more rated voltage and less rated current compared to the lap-wound machine.