Note: The answer choices are :
a) Increased
b) Decreased
c) stayed the same
Answer:
The correct option is Increased
The magnitude of the electric field potential difference between the wingtips increases.
Step-by-step explanation:
The magnitude of the electric potential difference is the induced emf and is given by the equation:

where l = length
v = velocity
B = magnetic field
As the altitude of the airplane increases, the magnetic flux becomes stronger, the speed of the airplane becomes perpendicular to the magnetic field, i.e.
,
the induced emf = vlB, and thus increases.
The magnitude of the electric field potential difference between the wingtips increases