An aircraft of mass \(3 \times 10^5 \mathrm{~kg}\) with total wing area \(400 \mathrm{~m}^2\) is in a level flight at a speed of \(540 \mathrm{~km} \mathrm{~h}^{-1}\). The density of air at its height is \(1.2 \mathrm{~kg} \mathrm{~m}^{-3}\). The fractional increase in the speed of the air on the upper surface of its wings relative to the lower surface is ____ \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.