Final answer:
The net magnetic force on the wire is 2/BL in the +z direction. Therefore, the correct option is B.
Step-by-step explanation:
The net magnetic force on the wire can be determined using the formula F = I × B, where F is the force, I is the current, and B is the magnetic field.
Since the current in the wire is in the positive z-direction and the magnetic field is also in the positive z-direction, the force would be in the same direction as the current and the magnetic field, which is in the +z direction.
Therefore, the correct option is B.
Your question is incomplete, most probably the complete question is:
4. A straight wire is bent into the shape shown. Determine the net magnetic force on the wire when the current /travels in the direction shown in the magnetic field B.
a. 2/BL in the?z direction.
b. 2/BL in the +z direction
c. 4/BL in the + z direction
d. 4/BL in the?z direction
e. zero