What effect do slight increases in the angle of attack of an airfoil typically have?

Slight increases in the angle of attack of an airfoil typically lead to an increase in lift due to the way airfoil design and airflow dynamics work. When the angle of attack—the angle between the chord line of the airfoil and the relative wind—changes, this affects how air flows over and under the wing.

As the angle of attack increases, the airfoil can generate more lift because the air has to travel faster over the upper surface compared to the lower surface. This difference in airflow results in lower pressure above the wing and higher pressure below it, creating a lifting force. This principle is derived from Bernoulli's principle, which states that an increase in a fluid's velocity results in a decrease in pressure.

However, it is important to note that there is an optimal angle of attack, beyond which lift will begin to decrease due to flow separation and stall conditions. In modest increases, up to that point, lift tends to increase.

The mention of the other options highlights that while drag can increase with increased angle of attack due to adverse pressure gradients and potential flow separation, the most direct effect on lift is the increase that occurs with slight increases in angle of attack. Thus, the choice indicating an increase in lift is the most