Question

. A student claims that if lighting strikes a metal flagpole, the force exerted by the Earth’s magnetic field on the current in the pole can be large enough to bend it. Typical currents generated from a lightning strike are 104 to 105 amps. Is the student’s opinion justified? Explain your reasoning?

Answer 1

Answer:

Explanation:

Given that, current generated from lightning range from

10⁴ A < I < 10^5 A

We know that,

The magnetic force is given as

F = iLB

The magnetic field on the earth surface is

B = 10^-5 T

So, let assume the worst case of a 15m flag pole

L = 15m

Then,

F = iLB

F = 10^5 × 10 × 10^-5

F = 15 N

Therefore, 15N is fairly strong so it will come to the material that was use for the material of the flag pole.

Therefore, it is possible that the student is right depending on the material of the flag pole.