Question 687Steam Plants - Assistant Engineer

The correct answer is D) decrease. As lube oil absorbs moisture, its dielectric strength will decrease. This is because moisture acts as a contaminant in the oil, reducing its insulating properties and making it a better conductor of electricity. As the dielectric strength decreases, the oil becomes less effective in insulating and protecting electrical components in the system. The other answer choices are incorrect because: A) an increase in viscosity would actually decrease the dielectric strength, not increase it; B) an increase in viscosity would also decrease the dielectric strength; and C) the dielectric strength cannot remain the same as it is negatively impacted by the absorption of moisture in the lube oil.