Final answer:
The magnitude of the magnetic field required to exert a force of 2.4 x 10^-4 Newtons on a wire carrying a current of 12 amperes and measuring 30 centimeters in length, placed perpendicular to the field, is 6.67 x 10^-4 T (teslas).
Step-by-step explanation:
The student is asking about the magnetic field that would exert a force on a segment of conducting wire with an electric current flowing through it. This is a classic example of applying the magnetic force equation F = BIl sin(θ), where F is the force in newtons, B is the magnetic field in teslas, I is the current in amperes, l is the length of the wire in meters, and θ is the angle between the wire and the magnetic field.
To solve for B, we can rearrange the formula: B = F / (Il). Given that the force F is 2.4 x 10-4 Newtons, the current I is 12 amperes, and the length l of the wire is 30 centimeters (which is 0.3 meters, since we need to use SI units), and assuming the wire is perpendicular to the magnetic field (which means θ = 90° and sin(θ) = 1), the calculation would be B = (2.4 x 10-4 N) / (12 A * 0.3 m).
Therefore, the magnitude of the magnetic field is 6.67 x 10-4 T (teslas).