Answer
The student is mistaken.
Work Step by Step
Equation 27.19 tells us the magnetic force $\vec{F}=I\vec{l}\times \vec{B}$.
Generously assuming a current of 100000 amperes, and using the earth’s magnetic field strength of $0.00005\;T$, calculate the maximum sideways force on a 10m-meter length of the flagpole.
$$F_{max}=(100000A)(10m)(0.00005T)=50N$$
This is approximately the weight of a small bowling ball and is not nearly enough to bend the flagpole, especially when we remember that the force is only momentary and spread out over the entire length of the pole.
