Answer
(a) The minimum possible magnitude of the magnetic field is $0.50~N$
(b) The information enables us to calculate the minimum possible magnitude of the magnetic field in the case when the angle $\theta$ is $90^{\circ}$. However, the magnitude of the magnetic field could be greater than this magnitude depending on the angle $\theta$.
Work Step by Step
(a) We can find the minimum possible magnitude of the magnetic field:
$F = I~L~B~sin~\theta$
$B = \frac{F}{I~L~sin~\theta}$
$B = \frac{4.12~N}{(33.0~A)(0.25~m)~sin~\theta}$
$B = \frac{0.50}{sin~\theta}~T$
The minimum possible magnitude of the magnetic field is $0.50~N$
(b) The information enables us to calculate the minimum possible magnitude of the magnetic field in the case when the angle $\theta$ is $90^{\circ}$. However, the magnitude of the magnetic field could be greater than this magnitude depending on the angle $\theta$.
