Question 43General Subjects - QMED

The correct answer is B) An oil with a high viscosity index would have a relatively low rate of change of viscosity as the temperature changes. The viscosity index (VI) of a lubricating oil is a measure of how the oil's viscosity changes with temperature. An oil with a high VI has a relatively small change in viscosity as the temperature changes, compared to an oil with a low VI. In other words, a high VI oil maintains a more consistent viscosity over a wider temperature range. This is a desirable property for lubricating oils, as it helps ensure consistent lubrication performance. The other answer choices are incorrect because they describe the opposite relationship between VI and viscosity changes. A high VI oil would not have a high rate of viscosity change with pressure (A), nor a high rate of change with temperature (D). The correct answer is that a high VI oil has a relatively low rate of viscosity change as the temperature changes (B).