In induction motors, the maximum power factor is influenced by the dispersion coefficient. The dispersion coefficient represents the spread or variation in the reactance of the motor windings. When the dispersion coefficient is increased, there is a large decrease in the maximum power factor.
This is because a higher dispersion coefficient leads to a greater variation in the reactance of the motor windings, causing an increase in the reactive power component. As a result, the power factor decreases, indicating a larger phase angle between the voltage and current waveforms.
Therefore, the correct answer is B. Increased dispersion coefficient results in a large decrease in the maximum power factor.