#### Answer

(a) The magnetic field strength is the smallest at point F.
(b) The magnetic field strength is the largest at point A.

#### Work Step by Step

(a) When magnetic field lines are farther apart from each other, the magnetic field strength is weaker. Therefore, the magnetic field strength is the smallest at point F.
(b) When magnetic field lines are closer together, the magnetic field strength is stronger. Therefore, the magnetic field strength is the largest at point A.