Question

In a Synchronous Motor What would you expect power factor to do if we kept lowering field current beyond the point where Stator current is at its lowest?

A) Become increasingly Leading

B) Become increasingly Lagging

C) Approach unity power factor

Answer 1

As indicated in the figure and as mentioned in question ,

Stator current is reduced beyond its Lowest value

1. Thus from the figure we can observe that at the point when the stator current is lowest the power factor is unity .

2. But as the the field current is reduced further the power factor will become lagging power factor .

3. Thus (B) is the answer to the question