How is lift generated on an aircraft wing?

Lift is generated on an aircraft wing primarily by the differential pressure between the upper and lower surfaces of the wing. This phenomenon is rooted in Bernoulli’s principle, which states that an increase in the velocity of a fluid is accompanied by a decrease in pressure.

As the aircraft moves through the air, the wing's shape—designed to be airfoil-like—allows air to flow faster over the top surface than the bottom surface. This speed difference creates a lower pressure on top of the wing compared to the higher pressure on the bottom, resulting in an upward force known as lift. The effective design of the wing, known as its airfoil shape, optimizes this pressure difference, enhancing the lift generated.

The other options do not primarily account for how lift is generated: while the wing's shape contributes to airflow characteristics, it is the pressure difference that is fundamental to lift. The velocity of the air beneath the wing does play a role in the overall aerodynamic efficiency but is not the sole factor in generating lift. Additionally, the weight of the aircraft is a significant factor in flight but does not create lift; rather, lift must overcome weight for the aircraft to ascend. Thus, option B correctly identifies the primary mechanism by which lift is produced.