There seems to be a lot of confusion/disagreement about how magnetic fields affect sharks. Many claim that they are strong repellents (not attractants) while others conclude that they have no effect on behavior. My opinion is that sharks might even send out weak electrical currents and test the current perturbations for the presence of potential prey and obstacles; a sort of active and/or passive radar or sonar-like detection. Of course sharks have been around for a long time and, according to shark paleontologists (some I have talked to personally), they have evolved considerably since even the Mesozoic. So there is no reason to think that all shark types use this sense the same way or for the same purposes. The people doing the two following videos come to different conclusions in their field tests but keep in mind that the sharks they are using as subjects belong to different taxa. The shark shown in the video by Google in the original post belongs to yet another taxon.
https://www.youtube.com/watch?v=oSkJJkY0MJohttps://www.youtube.com/watch?v=-MDkKOMLSb4The one thing that all seem to agree on is summarized below:
Oh, the shark, babe, has such teeth, dear
And it shows them pearly white
Just a jackknife has old MacHeath, babe
And he keeps it, ah, out of sight
Ya know when that shark bites with his teeth, babe
Scarlet billows start to spread
Fancy gloves, oh, wears old MacHeath, babe
So there's never, never a trace of red
Now on the sidewalk, huh, huh, whoo sunny morning, un huh
Lies a body just oozin' life, eek
And someone's sneakin' 'round the corner
Could that someone be Mack the Knife?
There's a tugboat, huh, huh, down by the river don'tcha know
Where a cement bag's just a'drooppin' on down
Oh, that cement is for, just for the weight, dear
Five'll get ya ten old Macky's back in town
Now d'ja hear 'bout Louie Miller? He disappeared, babe
After drawin'...
https://www.youtube.com/watch?v=yYZY9P4O4cQ