Linus builds an electrical circuit with a battery and with wires that carry the current. as the battery weakens, the current also weakens. how does this affect the magnetic field around the wires? a. the field gets stronger. b. the field gets weaker. c. the field changes direction. d. the field disappears completely.

It gets weaker, because that's a principle of electromagnets. The field force is directly proportional with tension.  

The correct answer is option (B).

Explanation:

The current carrying wire produces the magnetic field around it. More the current in the wire, stronger will be the magnetic strength around the wire. The magnetic field is stronger near this wire.

The direction of the magnetic field depends on the direction of the current.

In the given problem, Linus builds an electrical circuit with a battery and with wires that carry the current.The strength of the magnetic field depends on the amount of current flowing in the wire.  As the battery weakens, the current also weakens.

Therefore, the magnetic field around the wires is weaker.